CHAPTER 10 - USDA ARS

CHAPTER 10

l BORATORY AND FIELD MEASUREMENTS

Dell l1is L Corwin S M Lesch and D B Lobell

I TRODUCTION

Iii gta linity refers to the presence of major dissolved inorganic solutes [h~ ~(l i l solution (Le aqueous liquid phase of the soil and its solutes) 1 n consist of soluble and readily dissolvable salts including charged

lL- (eg a+ K+ Mg+2 Ca+2 C) HCOj NOi 50-2 and C032) 11m lute clOd ions that combine to form ion pails The primary

bull 01 alts in Roil and water is the geochemical weathering of rocks the earths upper tra ta with atmospheric depcsition and anthroshynk lCtivities s rv ing as secondary sources The predominant mechashym~au sing the accumulation of salt in the roo tzone of agricultural soils

In lIf water through evapotranspiration (ET the combined processes ~dP(lru tion from the soil urface and plant transpiration) which selecshy) removes wa ter leaving salts behind n cu mulati n of soil alinity can result in reduced plant growth UllU yie lds and in severe cases crop faiiJre Salinity limits water

bullbull Io-t by plants by reducing th osmotic potential making it more diffi shylllClr the pLant t extract wa ter Salinity may also cause specific-ion toxshy

leg Ja ion toxicity) or upset the nutritional balance of plants In lilllnn the salt composition of the soil water influences the omposition

linrL on the exchan ge complex of soil particles which influences soil ITIll abil it and til th Irriglted agricul ture w hich accounts for 35 to 40 of the world s bull I IOld and fiber is adversely affected by soil salinity on roughly half 11 irriga ted soils (t taling about 250 million ha) with more than 20 mil-

h severely affected by salinity worldwide (Rhoades and Loveday 11 Be ause of the potential detrimental impacts of soil salinity accushy

ul1ti(Jn it is a crucial soil chemical property that is routinely mesured

295

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Corwin DL Lesch SM and DB Lobell 2012 Laboratory and field measurements 13In WW Wallender and KK Tanji (eds) ASCE Manual and Reports on Engineering Practice No 71 Agricultural Salinity Assessment and Management (2nd Edition) ASCE Reston VA Chapter 10 pp295-341
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296 AGRICULTURAL SALI NITY ASSESSM ENT AND MANAGEM ENT

and monitored This chap ter describes common field and laboratory t niques for measuring salinity in the soil and water w ith di u sian their practicability and reliability

FACTORS AFFECTING SOIL SALINITY

The accumula tion of soil salinity is a consequence f a variet pro esses some of which are illu trated in Fig 10-1 In arid and semian

fl areas for example where pre ipitation is less than evaporation salts lJ accumulate at the soil surface when the depth to the water table is I t r

than 1 to 15 m depend ing on the soil texture The accumulation of salts 11 r

the soil surface is the consequence of the upward flow of water and ur sequent transport of salts due to capillary rise driv n by the evaporatill p rocess However the most common ca use for the accumulation of ai DIRE is ET by plants w hich results in an increase in salt concentra tion IIi depth through the roo tzone (see graph in Fig 10-1) and th accumulatil Till

of salts below the rootzone The lev I of salt accumulation within an (lrator

below th r otzone due to ET depends on the fraction of irrigation or prl Ii I ir flwnt (

What Causes Salt Accumulation ftP~

FIGUR E 10-1 Variou s examples of how salts accumulate in soil

rm be ClIJ1gttil m ntl IIll r

1 ) l

lion e llt~ I

prop I

Ilw 1 lldiu [ II Ilf 1tIi

hlmil IlI lab 111S 01

I nn ll

mnlll 1 i

lIImpll III the I m nl ( l P_t it til 01 lIrtmiddotd b

ration it~ ~~

~ ff _ ~ o

Salinity DistrioolTOl in the Root lone

lt NA E ENl

iIl laboratllnlt with djscu~~ j ll

Ke of c ri I ~ arid and Slml pora tion lt1 1t~ Wilter tabl~ i~ I rnu lati n ofSl t I o f w ater elnd up ~y the evaporall muJation 01 1

m entrati Jl Ith the aCCumul1tion anon within nd irrigation r rfl

~tion

LABORATORY AN D FIELD MEASUREMENTS 297

n Ihat flow beyond the rootzone referred to as the leach ing fracshyF the L increas s the total alts within the rootzone d cr ase thl r remova l from the rootzone by Jeach ing A third process

t Lommllll in the northern Great Plains of the United Sta tes is the r 10 lIf sd line seeps There are s veral forms of saline seep differing

lIleJn_ of developmen t In general saline seeps form downslope t areas in loca tions where d ischarg is occurr ing because o f the

ui low conductivity layer and shallow w ater table (Fig 10-1) I IL)ched from the upslope recharge area which tends to be an hiLher conducti vity than the downslope discharg area Once the nd alts from upslope reach the downslope low cond uctivity

tl1 1c urnulate and are forced to the surface by evapora tion

IKECT A 0 lNDIRECT ANALYSIS OF SOIL SALINITY

(l tcornmon technique for the measurement of so il salinity is labshyJnu lysis of aqueous extracts of oil samples Soil salinity is quanti shy

m tern llf the concentrabon of total salts in the soil The measureshyIII lh~ total sa lt concen tration of the aqueous extracts of soil samples

bcdnnc either d irectly through the chemical analysis of the chemical tlul thilt comprise so il salinity or indirectly through th e measureshy

I I ( Iectrical conductiv ity (EC) The chem ical species of p r imary 1 in ~a lt-affected soils include four major cations (N -1 K+ Mg+2 md fuur major anions (Cl- HC0 3 S042 and 0 32) in the soil o lushychJngeable cations (Na+ K+ Mg -- 2 Ca +2) and the p recipitated kium carbonate (lime) and calcium sulfate (gypsum) O ther soil

rtles of concern in salt-affected soils include pH water con ten t f IUIJtion paste sodium adsorption ratio (SAR) and exchangeable

11m percentage (ESP) Deta iled analytical techniques for measuring Illh C ~alinit -rela t d properties can be fo und in Methods of Soil i (Part 3 Sparks 1996 Part 4 Dane and opp 2002) H owever a

ni I I analysis of the salinity-related properties of primary concern is N r- and cost-intensive to b practical pa rticularly hen large n umshy11 _lmp1c5 are invol ed such as field-scale assessments of salinity

III middotntly the salinity of aqueous extracts of soil samples has been t dttln measured by Ee

I 1 1( 11 known that th EC of water is a function of its chemical salt rl~ltilln and total salt concentration (Us Salinity Laboratory 1954)

Ih laboratory soil sa linity is commonly determined from the measureshyO oi the EC of soil-solution extracts where the current-carrying

~ll1t of the soil solution is proportionzll to the concen tra tion of io in -oluhlln The total concentration of the soluble salt in soil is measshyJv EC of the soil solu tion in dS m Over a range of mixed salt

298 AGR ICULTURAL SALINITY ASSESSMENT AND MA NAGEM ENT

concentrations commonly found in soils (1 to 50 meq L-I) total salt CO~ centration (C) in meq L -1 is linearly related to electrical conductance the solution by Eq 10-1

C = 10middot ECW 2o C (J

where ECw 25 C is the electrical conductivity of the soil solution r

~

f~ enced to 25 deg (dS m-1) If C is measured in mg L--1 or ppm then e shyrelated to ECw 25 c by a factor of 640 (i e C = 640middot Ctv 25 dOlrl

broader range of salt concentrations (1 to 500 meq L- 1) the relation~h between C and ECv25 C is no longer linear and is best fi t with a lhir order polynomial r an exponential equation Another useful relationh is between osmoti c potential (jJ) and EC where jJ in bars is retal to EC wt9 25 C by a factor of -036 (eg jJ7T = -036 EC 2i C f r~ EC1U 25 0C 30 dS m-1)

Theoretical and empirical approaches are available to predict the pound( a solution from its solute composition Equation 10-2 is an example (II

theoretical approach based on Kohlrauchs Law of indep ndent migr tion of ions where each ion contributes to the current-carrying abilian electrolyte solution

(UI-

where EC is the specific conductance (dS m-1) EC is the ioni specific (

ductance (dS m I) C is the concentration of the ith ion (mmol L -I) e

the ionic equivalent conductance at infinite dilution (cm2 S mol- I) and ~middot an empirical interactive parameter (Hamed and Owen 1958) Equation llF shows an empirical equation developed by Marion and Babcock (1976)

log TSS = 0990 + 1055 log EC (r2 = 0993)

where TSS is the total soluble salt concentration (mmolc L-1) Temperature influences EC consequently EC must be referenced tl

specific temperature to permit comparison Electrolytic conductili increases at a rate of approximately 19 per degree centigrade incred in temperature Customarily EC is expressed at a reference temperatun of 25 degC The EC measured at a particular temperature t (in 0c) Ee0

be adjusted to a reference EC at 25degC EC 2S DC using Eg 4 from usn Handbook 60 (Us Salinity Laboratory 1954)

ECs C = It EC (1(l

I here 114t)=1 I

METH SOIL

1111lt11

Elect

h -II

d ti tI i I ured nd I

Ie Ii 111

he

In 0

rntl

Ii lIt I

11

middotNA EM[NT

L - I) to tal ~l1t cal cond u llnl

IO-t

soil sol uti )

) predict th bull E( It s an ex mp 01 iependent mi m arrying abilit 0

(10 2

onjc specific llln m m I L 1) A I

LABORATORY AND FIE LD MEASUREMEN TS 299

04470 + 14034 exp( - t26S15) [from Sheets and Hendrickx

IIpoundTHODS OF LABORATORY LYSIMETER AND PLOT-SCALE 1 ALINITYMEASUREMENT

t nca lly four principal methods have been used for measuring soil h In the lab ra tary in soil Iysimeter columns and at field-plot III the EC of soil solution at or near field capacity of extracts at

r thln normal water contents (ie including saturation and soil to rJtil1~ of 1 1 1 2 and 1 5) or of a saturation paste (2) in-situ measshynl of dectrical resistivity (ER) (3) noninvasive measurement of EC IlliTomagnetic induction (EMI) and most recently (4) in-situ rlm nt of EC with time domain reflectometry (TDR)

dll~nnine the BC of a soil solution extract the solution is placed in Ll1nlillnmi two electrodes of constant geometry and distance of sepshyn n electrical potential is imposed across the electrodes and the Ifkl of the solution between the electrodes is measured The measshy1nductance is a consequence of the solutions salt concentration

himiddot de trode geometry whose effects are embodied in a cell cons tant lslJnt potential the current is inversely proportional to the solushyrt istdnce as shown in Eq 10-5

mor- ) and 13 i8) Equation 10shyabcock (1 Y7n)

( II

im rtl temp rltlture

n degC) EC I m 4 fro m usn

(10

(10-5)

I is the electrical conductivity of the soil solution in dS m- I at

m~ rJl urc f (QC) k is the cell constant and R is the measured resistance

t temperature t One dS m - 1 is equivalent to one mS em - 1 and mmhncm- 1 where mmho cm- 1 are the obsolete units ofEe

Pt for the measurement of EC of a saturated soil paste (ECp) the

bull

f11lioation of soluble salts in disturbed soil samples consists of two -kp (1) preparation of a soil-water extract and (2) the measureshy

rlIt the salt concentration of the extract using EC Customarily soil nlt hlS been defined in terms of laboratory measurements of the EC

tract of a saturated soil paste (ECe) This is because it is irnpractishyrrou tine purposes to extract soil water from samples at typical field

rfumtents consequently soil-solution extracts must be made at satushy1lI higher water contents The saturation paste extract is the lowest

l-ater ratio that can be easily extracted with vacuum pressure or ritU)ltl tlon while providing a sample of sufficient size to analyze TI1e

300 AGR ICULTURAL SALINITY ASSESSM EN T AND MANAGEMENT

water content of a saturation paste is roughly twice the field capilotl most soils Fu rthenn re ECe has been the standard measure of used in sal t-to l rance plant studies Most data on the alt tolernn crops have been expressed in terms of the EC of the saturation extract (Bre I r tal 1982 Maas 1986)

U11for ttmately the pa r ti tioning af solutes over the three soil (gas liqu id solid) is in fl uenced by the soil-to-water ratio at whicr extract is made so the ratio needs to be standardized to obtain resultt can be applied and interp reted universally Commonly lIsed rabos other than a sa turated soil paste are 1 1 1 2 and 1 5 soil-to- m ix tures The e tracts are easier to p repare than saturation r extracts With the xception of sandy soils soils containing gypsum organ ic soil the concentrations of salt and individual ions are appn ma tely diluted by about the sam ra tio between field conditions aI d extract for all -amples which allows conversions between water coni u ing d ilution fa ctors The conversion of EC from one extract to ano commonly done using a simple dilution factor For example if the ~r metric saturation percentage (SP) is 100 then ECe = ECll = 5 EC if SF = 5010 then ECe = 2 ECl1 = 10middot EC5 However th is is not r~ mended because of potential dissolution-pr cipitation reactions that occur At best the use of a d ilu tion factor to convert from One extra another is an approximation_

Any d ilution above field water contents introduces errors in the in~ preta tion of data The greater the dilution is the greater the devia between ionic ratios in the sample and the soil solution under field cor tions These errors are associated with m ineral dissolution ion hydn sis and changes in exchangeabl ca tion ratios In particular soil samr con taining gypsum deviate the most because the calcium (Ca) and sull concentra tion rem ain nearly constant with silmple dilution while the centra tions of other ions decrease with dilution The standardized re tionship between the extract and the conditions of the soil solu tion in ~ field for different soils is not applicable with the use of soil-to-wJk abo e saturation However the recent development of Extract Crem Sl~ ware by Suarez and Taber (2007) illlows for the accurate conversion f one extract ratio to another p rovided sufficient chemica l informati n known (for example knowledg of the major cations ilnd anions an p resence absen e of gypsum) Th disadvantage of determining ~ salinity using a soil sample i th time and labor required which tran lates into high cost However there is no more accurate way of meaSl1 ([1 soil salini ty than with extracts from soil samples

Prior to the 1950s much of the data on soil sdlinity were obtained ~ using a 50-mL cylindrical onductivity cell referred to as a Bureau I

oils cup filled w ith a satur ted soil paste to estimate soluble-saltcoC f( centrations by measuring the ECI This approach was fast and easy ( IT l~

n one xtrl t

Jrs in the jot r th d e iilllon ier fieJd cond 1 ion hdrul I soil samp =a) and u llnlt while Il ll tOn

dardLced rL iO u tion in th soil- t -watr

act CllclI1 ott l vers ion from nformat iu i j an i n lt1n -rmin ing ~nJI w hich tran of measuring

obtained b I Bured U 01 ble-saJ t con ld easy eln-

LABORATORY AND FIELD MEASUREMENTS 301

1I It wa used to map and diagnose salt-affected soils When Reitshynd Ilcox (1946) determined that plant responses to soil salinity ~ more closely with the EC values of the saturation paste extract ( ~ll paste was discontinued A theoretical relationship between r has since been developed to overcome the cells shortcomshy

Th I _ I~ done by developing a simple method of determining the Iri I ter and volumetric solid contents of the saturation paste udmce of the sample surface and the current pathway of the (hl (ell (Rhoades et al 1999b) Even so the relationship between

dFe is complex consequently the measurement of ECp is not recshyld tlxcept in instances where obtaining an extract of the saturashy

ll IS not possible or is impractical Figure 10-2 graphically illusshytheoretical complexity of the relationship between ECp and ECe

till dual parallel pathway conductance model of Rhoades et al b

linit can also be determined from the measurement of the EC of lutlon (Ee ) where the water content of the soil is less than satushy~ud lly at field capacity Ideally ECw is the best index of soil salinshyuse this is the salinity actually experienced by the plant root Nevershy1( has not been widely used to express soil salinity for various

11 ) it varies over the irrigation cycle as the soil water content gt() it is not single-valued and (2) the methods for obtaining soil lmples at typ ica II field water contents are too labor- time- and

ntlllsive to be practical (Rhoades et a1 1999b) For disturbed soil It oil solution can be obtained in the laboratory by displaceshyLumpaction centrifugation molecular adsorption and vacuum- or

SP=20 10

40 60

80 - 8 100 I

E 6(J tJ- 4

tI

0 W 2

1 2 3 4 5 ECp(dS mshy1)

IRE 10-2 Theoretical relationship between ECe and ECp based on the dual ( II11th pay cOllductance model of Rhoades ct al (1989ab)

Electrolytic ~~~ir~ element ~

Platinum electrodes

can

302 AGRICULTURAL SALINITY ASSESSMENT AND MANAGEMENT

pressure-extraction methods For undisturbed soil samples ECdetermined with a soil-solution extractor (Fig lO-3a) often referred to a porous cup extractor or using an in situ imbibing-type porous-matrn salinity sensor (Fig lO-3b)

(a) Soli solution extractor system

Manifold

Vacuum

Solution

Suction cup extractors

(b) Porous-matrix salinity sensor

Spring

Housing

FIGURE 10-3 Instruments for obtaining soil-solution extracts at less than Imiddot uration including (a) soil-solution extractor system (from Corwin 2002a) Ill (b) porous-matrix salinity sensor (from Corwin 2002b) Reprinted with PerIII

sion from Soil Science Society of America

303 -JAGEME T

np] sEC n Iften referfld t

ctors

pin

Spring

80f(ATORY AN D FIELD MEASUREMENTS

up ~(liJ ~(1lution extractors include zero-tension and tension (or lip HIStorically suction cups have been more widely used No

Iiution sampling device will perfectly sample under all condishyIt I Important to under tand the strengths and lim itations of a

dltlrminr when to apply certain sampling methods in prefershythlr m thods In structured soils suction cups do not sample

prcitrlntial fl ow paths Zero-tension cups will almost always I ~Iturated flow which is more closely associated with prcfershy

II hannels and tension samplers will more efficiently sample II j 110 within soil aggregates Zero-tension cups represent the ntralion whereas the tension samples are Ilpproximations of ntntra tions

1 design of a su tion cup apparatus consists of a suction cup lit liOll bottle manifold (if there is more than one suction cup)

111 trap iln app lied vacuum and connec tive tubing (Fig 10-3a) I rnn iplc behind the operation of suction cup extractors is I uLb n (preferably the suction at field moisture capacity) is n I lhe porous cup This suction opposes the capillary force of

I fillJ capilci ty causing soil solution to be drawn across the II uf the cup as a result of the induced pressure gradient The lution is stored in a sample collection chamber This approach

tll1lsoil ~olution is viable when the soil-water matric potential is 10 l~out - 30 kPa (kilopascals a standard unit of pressure) Iintly sensor consis t of a porous ceramic substrate with an

pl1linum mesh electrode which is placed in contact with the In IIlrt the EC of the soil solution that has been imbibed by the lig JO-3b) The salinity sensor contains a thermistor designed to rurl -L(lrrect the EC readings Both the electrolytic element and

tor 011 salt sensor (Fig 1O-3b) must be calibrated for proper opershyhbralilln is necessary because of (1) the varia tion in water r tenshyptltllsi ty charac t ristics of each ceramic and (2) the variation in

pa ing both of which cause the cell constant to vary for each I[ TIlt calibration can change with time so periodic recalibration f

f t Jlious advantages and disadvantages to measuring EC using nhnn c tract(lrs or soil salinity sensors The obvious advantage is

I berng measwed but this is outweighed by the disadvantages u~h the sample volume of a soil-solution extracto r (10 to 100 cm ) II an Irder of magnitude larger than a salinity sensor (1 to 2 cmJ

)

lin Gignificantly limited sample volumes consequently there are lllubts ilbout the ability of soil-solution extractors and porousshyllillil) ensors to provide representative soil-water samples p arshyltikmiddotld ~cales (England 1974 Raulund-Rasmussen 1989 Smith et al IIllwterogeneity significantly affects chemical concentrations in

304 AGRICULTURAL SALINITY ASSESSM N AND MA NA EM E T

the soil solution Because of their small sphere of measur ment neil solution extractors nor salt sensors adequately integrate spatial variaoil (Amoozegar-Fard et al 1982 Haines et al 1982 H art and LOwery 1 -Biggar and Nielsen (1976) suggest d that soil-sol ution samples are JI samples that can provide a good qualitative mea5urem nt of soil 1

tions but are not adequate quantitative measurements unless th fIe scale variability is adequately established Furthermore salinity sen demonstrate a response time lag that is d pendent on the diffus ion af il betw n the soil solution and s Ju tion in the porous c amic whkh affected by (1) the thickness of the ceramic conductivity cell (2) the di sion coefficients in soil and ceramic and (3) the fraction of the ceraIT surface in contact with soil (Wesseling and Oster ] 973) The salinity sor is generally considered the least desirable method for measuring Ie because of its low sample volume unstable caHbrati n v r time (I

slow response time (Corwin 2002b) Soil-solution xtractor hav t

d rawback of requiring consid rable maintenance due to racks In

vacuum lines and clogging of the ceramic cups with alga and fine particl s Both solution extractors and salt sensors are c nsidered Ill and labor-intensive

The ability to obtain the EC of a soil solution when the water content at or less than field capacity wh ich are the water ca nt nt5 most co monly found in the field is considerably more d ifficult than extract il water c ntents at or above saturation because of the pre ure or suclil r quiJed to remove the soil solution at field capacity and lower wa ter c rr tents The EC of the saturated paste is the easiest to obta in fo llowed b the EC of extracts greater than SP followed by the EC of extracts less th ~

SP However EC is mos t preferred consequently either measuring E or being able to relate the BC measurement to ECe is r itical The tClh niques of ER EMl and TOR measure ECn which is discussed in the nel section

Electrical Resistivity

Because of the time and cost of obtaining soil-solution extracts and thl lag time associated with porous ceramic cups developments in the med middot urement of soil Ee shilted in the 1970s to the measurement of the soil [C of the bulk soil referred to as apparent soil electrical conductivity (Ee Apparent soil electrical conductivity p rovides an immediate easy-to-tak measurement of conductance with no lag time and no n ed to obtain bull soil extr ct However Ee is a complex measurement that has been misshyinterpreted and misunderstood by users in the past due to the fact that 1

is a measure of the EC of the bulk soil not just a measure of the condu(middot tance of the soil solution which is the desired measurement since th soil solution is the soil phase that contains the salts affec ting p lant rootgt

lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I

r mea 11 ring I cri tical 1h tl h cussed in thl 11 I

ilgts~ Ih n

n ex tra t5 and th 1ents in the m lent of the soil F gtnducli ILv (l ) liate ea y~to- t need to obi in

1a t has b en J11 i t ) the fact th I II r~ of he cond u ement s inCt I h cting p i nt rll( I

LABORATORY A D FIELD MEASUREM ENTS 305

In 11

k

J

rt

ldl

t ltlmprehensi e body of research concerning the adaptation Illa tion of geophy leal techniques to the measurement of soil

Ithin the rootzone (top 1 to 15 m of soil) was compiled by scishyJl th~ Us Salinity Laboratory The most recent rev iews of this

(II rc~carch can be found in Corwin (2005) Corwin and Lesch I Jnd Rhoades et al (1999b)

istivity (ER) was originally used by geophysicists to measshyis tivity of the geological subsurface Electrical resistivity methshy

[I l the mcasmement of the resistance to current flow across four ill s~rted in a straight line on the soil surface at a specified disshy

bt tween the d ectrodes (Corwin and Hendrickx 2002) The elecshyart (llnnectcd to a resistance met r that meaSUTes the potential grashyII tween the ClilT nt and potential electrodes (Fig 10-4) These

Wl developed in the second decade of the 1900s by Conrad mb rger in france and Frank Wenner in the United States for the tllm of near-surface ER (Burger 1992 Rhoades and Halvorson though two elltctrodes (one current and one potential electrode)

U ed lhe stability of the reading is greatly improved with the use r eitClroLies

istance is converted to EC using Eq 10-5 where the cell conshy III thilt equation is determined by the electrode configuration and l f11C depth of penetration of the electrical current and the voltUne

l~uremcnt increase as the interelectrode spacing increases The fourshyIJl lOllfiguration is referred to as a Wenner array when the four

arc equidistantly spaced (interelectrode spacing = a) For a

Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1

---------------- R1--------------------JI+-R2 --J [IRE 10-4 Schematic offour-electrode probe electrical resist ivity used to Ilppnrellt soil electrical conductivity From Corwin and Hendrickx lJ litit permission from Soil Science Society of America


homogeneous soil the depth of penetration of the Wenner array is nar the soil volume measured is roughly 1Ta3

Other four-electrode configurations are frequently used as disclL by Burger (1992) Dobrin (1960) and Telford et al (1990) The influe of the interelectrode configuration and distance on ECa is reflected middot Eq10-6

EC lt0 _= ( 1000 ) (1~ G 21TR 1

t

where EC ll25 C is the apparent soil electrical conductivity temperature co rected to a reference of 25 degC (dS m- I ) and r 1 r2 Rv and R2 are the d~middot tances in cm between the electrodes as shown in Fig 10-4 For the Wenlll array where a = rl = r 2 = Rl = R2 Eq 10-6 reduces to EC = 1592M F and 1592 a represents the cell constant (k)

A variety of four-electrode probes have been commercially developtl1 reflecting diverse applications Burial and insertion four-electrode pmbc are used for continuous monitoring of ECa and to measure soil prolr ECa respectively (Fig 10-5ab) These probes have volumes of measurc

3ment roughly the size of a football (ie about 2500 cm ) Bedding proiJ with small volumes of measurement of roughly 25 cm3 were used to mltshyitor EC in seed beds (Fig 10-5c) but these probes are no longer comm~r

cially available Only the Eijelkamp conductivity meter and probe art commercially available which is similar in use and basic d esign to thL insertion probe in Fig 1O-5b

Measuring ER is an invasive technique that requires good contact between the soil and the four electrodes inserted into the soil cons quently it produces less reliab~e measurements in dry or stony soils thar a noninvasive measurement such as EM Nevertheless ER has a flex ibilshyity that has proven advantageous for field application that is the depth and volume of measurement can be easily changed by altering the spacmiddot ing between the electrodes A distinct advantage of the ER approach j that the volume of measurement is determined by the spacing between the electrodes which makes a large volume of measurement possible for example a 1-m interelectrode spacing for a Wenner array results in a volmiddot ume of measurement of more than 3 m3

This large volume of measureshyment integrates the high level of local-scale variability often associat lt

with ECa measurements

307

RL 10-5 EXllllfp les oj various Jour-electrode probes (a) bllrial probe rtJll1l1role lind (c) bedding probe

~AG[Mr1 I

mer arT] J a

mg rcumm an d prllbl ell design tll II

LABORATORY AND FIELD MEASUREME NTS

LABORAT RY AND FI ELD MEA5U308 AGRICULTURAL SALI NITY ASSESSM ENT AND MANAGEM I T

induces ci rcuJar edd y-current loops in the soi Because Ee is regarded as the standard measure of sallnitv a reiaul ~ between ECn and E r is needed to relate ECn to salinity The elationshlc between ECII and E e is linear when ECn is above 2 dS m -1 and is depend

Jnd El

~ on soil texture as shown in Fig 10-6 Rough approximations or EC fr ECn in dS m- 1 when EC 22 dS m - 1 are ECe = 35 ECn for fjne-textur soils ECe = 55 ECn for medium-textured soils and ECe = 75 Ee fo coarse-textured soils For ECn lt 2 dS 111- 1 the relation between ECq

is more complex In general at CII 22 dS m - 1 salinity is the dominant (0

ductive constihlent consequently the relationship between EC and EC linear However when BCa lt 2 dS m- I

other conductive properties (t g

water and clay content) and properties influencing conductance (eg bull density) have greatcr influence For this reason it is recommended tha below an ECa of 2 dS m -1 the relation between BCn and BCt is establi h by calibration The calibration between EC and EC is tablish d by nwa uring the Ee of soil samples taken at a minimum of three to four location within a study area where associated Een measurements have been taken These samples should reflect a range of ECns and should be collected om the volume of measurement for the ECn technol gy used (ie ER or E 11)

ElectTomagnetic Induction

Apparent soil electrical cond uctivity can be measured noninvasiveh with EMI A transmitter coil located at one end of the EMl instrume~1

45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a

FIGURE 10-6 Relationships between ECu and ECJor representative soil type found In tze northem Grmt Plains United States Mod~fied from Rhoades nlll Halvorson (1977)

Ih~~ It)OPS directly p roportional to the EC in (h 10-7) Each urrent loop generates a econe III(t is proportional to the value ot the u rrent fI trll tion of the secondary induced eLectromagne H1t~rc pted by the receiver coil of the instrum ~ i Tnuls i am lified and formed into an output 1 depth-weighted ECII bull The am~litude ~d ph ill differ from those of the pnmary ft Id as (eg d y conten t w ater content salinity) spa (lri ntati 0 frequency and dIstance from the c -t1chanoski 2002)

rhe m st commonly used EM conduc tivity in vadose zone hydrology are the Geonics E~ I ld Mississauga Ontario Canada) and the ]

IiltOl1 Ontad Canada) Th EM-38 has had ( (aLilln f r agricultural purposes b cause the d ~pondB roughl y to the rootzone (ie gen r al in~tnUl1ent is placed in the vertical COlI conftgu perp odiculaJ to the soil surface) th~ depth ICi m io the h rizontal coil conhguratlOn (EM the s il urface) the depth of the mlasurement ha an in t rcoil pacing of 366 m which cor J r th of 3 an d 6 ill in the horizon tal and ve resp ctively which extends well b yond 1111

FICUR - 10-7 chematic of the operation of eh lIItnt llsi17g (II EM-38

12

LA llORAT RY AN FJELD MEASUREMENTS 309

noninYJ i in slrum n

al ive nil 111 I Rlloadl rllld

fu lar eddy-cuIT nt loop in th soil with the magni tu d e of dir tly proportional to th EC in the vicinity of tha t loop

(h current loop genera tes a secondary electromagnetic field lIflIrllOnal to the value of the curren t flowing within the loop A

L)( the cCLlndary induced electromagnetic field from each loop is I J b~ lh receiver coil of the ins trumen t and the sum of these mpli fied and formed into an output voltage which is related to li~h t d C The amplitude and phase of the secondary field rr frnm those of the primary field as a result of soil properties

J uln tent water content salin ity) spacing of the coils and their Ion frequency and distance from the soil urface (Hendrickx and

ki Oll2) 01 I ommonly used MI conductivity met rs in soil science and

lone hydrology are the Geon ics EM-31 an d EM- 8 (Geonics f i 1lIga Onta rio Canada) and the DUALEM-2 (Dualem Inc )ntario Cmada) Th EM-38 has had considerab ly great applishyra~rictlltural purposes bee use the d epth of measurement correshywugh ly to the rootzone (ie generally 1 to 15 m ) When th e

menl i~ placed in the vertical coil configura tion (EM with the coils dlular to the soil sur face) the depth of measurement is about

In the horizontal coil configuration (EM with the coils parallel to urfl(c) the dep th of the mea urement is 075 to 10 m The EM-31

IOttfr oii spacing of 366 m which carre p nds to a penetra tion Ii 1 and 6 m in the horizontal and vertica l d ip ole orientations

IIV tmiddot which xtends well beyond the rootzone of agricultural

URE 10-7 Schematic of the operation of electromagnetic induction equipshyINIIg illl EM -38

31 0 AGRICULTURAL SALIN ITY ASSESSM ENT AND MANAGEM[NT

crops H owever the M-38 ha one major pi tfall-the need for calirshytion-which the DUALEM-2 does not require Fur ther details about operation of the EM-31 and M-38 equipment are discussed in Hendn I

and Kachanoski (2002) Documents concerning the DUALEM-2 canmiddot found in Dualem (2007)

Apparent soil electrical conductivity measured by EM at E m - 1 is given by Eq 10-7 from McNeill (1980)

(Ju

TimeDom

Time mll tiri ng nil llJR tI ~od r l

Ihl porou trltlU Ih l

Ilh TDR Irltl rl I r middotlalt

l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r

where EC is measured in S ill- I Hp and Hs are the intensities of the r mary and secondary magnetic fie1ds at the r c iver coil (A ill- I) J1 IXmiddot tive1yf is the frequency of the curren t (Hz) fLo i the magnetic permeJi ity of air (41T10 - 7 H m-I ) and 5 is the intercoil spacing (m)

Both R and EMI are rap id and reEable tech nologies f r the mea UI ment of ECn each with its advan tages and disadvantages The prim advantage of EMI over ER is that EMl is noninvasive so it can be used dry and stony soils that would not be amenable to invasive ER eq irshyment The disadvantage is that ECa measured with EMI is a dep~ weighted value that is nonlinear whereas ER provides an EC measu ment that is nearly linear with depth Mar specifically EMJ c ncentratl its measurement of conductance over the depth of penetration at shallo depths while ER is more uniform with depth Because f th lineari~

the response function of ER the EC for a discrete depth interval of oil ECv can be det mtined with the Wenner array by measuring the EC ~

successive la yers by increasing the in terelec trode spacing from nj 1 t(1 and using Eq 10-8 from Barnes (1952) for re istor in parallel

(l~

where aj is the interelectrode spacing which equals the depth of sam pling and a j - l is the p revious interelectrode spacing which equals th dep th of previous sampling Measu rements of ECa by ER and ffivfJ at th same location and over the same volume of meas urement are not compamiddot rable because of the nonlinearity of the response function with depth fur EM and the linearity of the response function for ER An advantage of ER over EMI is the ease of instrument calibra tion Calibrating the EM-31 and EM-38 is more involved then for ER equipment Howev f there is nIl

need to calibrate the DUALEM-2 in (2 )

IANAG uv1[N

lcr d eta ils nbll ll i I

lI ssed in J-l 11 In DUALEM-1 t n

EMI at EC In

(I

LMlORATORY AND FIELD MEASUREME NTS 311

I doma in refle tome try (TDR) was ini tia lly ad ap ted fo r use in ng J ter content 8 (Topp and Davis 1981 Top p e t a1 19801982) RIe hniqut i ~ be sed on the time for a voltage pulse to travel down

pTllbr ~nd back which is a function of the dielectric constant (E) of Iml~ media being meas ured Later D alton et a l (1984) dem onshy

tnt uti lity of TOR to also measure ECa The measurement of C rnR i basec on the a ttenuation of the ap plied signal voltage as it

Ih 1 medium of interest w ith the rela tive magnitude of energy IlJ to E (Wraith 2002)

1t-luring E f) can be det rmined through calibration (Dalton 1992) LJkulatlc with Eq 10-9 from Topp et a1 (1980)

lteru ities of Ihl pn o il (A rn I) n~

1agn tic pernlL1l1 (m)

cs for the mlcl 1I

tages The prima 0 it can b lIsld m nv~ iv ER tlUI

1 EM is a dlplh ~ an Ee mldiUr EMf conccntrlh tratio n at sha ll

of the l inliIril f )th interval 01 1111

aS lJring Ul( n_ IIf ing from II til lfaUel

(10- l

he depth of ianl which equals Ih nand EMl lt1t th It are not complshym w ith depth jpr

advan tag of f I 19 Ule E -31 Ind

er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J

r j the propagation velocity of an electromagnetic wave in free _9Y7 x lOR m 5 - 1) t is the travel time (s) l is the real length of the ~1t (m) I is the app arent length (m) as measured by a cable tester I the relative velocity setting of the instrument The relationship

n Ha nd f is ap proximately linear and is influenced by soil ty pe Pb llthmt and org-anic mL tter (Ja obsen and Schjonning 1993)

measuring the resis tive load imp edance acros the p robe (ZL) EC tit (l leulatec with Eq 10-10 from Giese and Tiemann (1975)

(10-10)

n t I the permittivity of free space (8854 X 10-12 F m- I) Zo is the

i mp~d ance (D) and ZL = Z J(2Vol VI) - I tl where 21 is the characshybL impedance of the cable tester Vo is the voltage of the pulse g nershyr lern-reference voltage and VI is the final reflected voltage at an

J ingly long time To referenc Ee ll to 25 oc Eq 10-11 is used

(10-11)

tfc k is the TDR probe cell constant (Kc [m- I] = poundocZol l) which is

t rmmed empirically Jantages of TDR for measuring EC include (1) a relatively nonshy

ilc nature since there is only minor interference w ith soil pruccsses ~n Jbility to measure both soil water content and ECn (3) an ability to

312 AGRICULTURAL SALI NITY ASSESSMENT AND MA NAGEyILJT

detect small changes in ECa under representative soil condition 4 capability of obtaining continuous unattended measmements unci lack of a calibration requirement for soil water content measuremell many cases (Wraith 2002) Even so TDR has not been tbe choice for the measurement of salinity whether in the laboratory or In

field consequently it will not be discussed in detail Soil ECn has become one of the most reliable and frequently used

urements to characterize field variability for application to precision culture due to its ease of measu rement and reliability (Corwin and 2003) Although TOR has been demonstrated to compar closeh other accepted methods of ECn measurement (Heimovaara et al Mallan ts et a1 1996 Reece 1998 Spaans and Baker 1993) it is still nO ficiently simple robust or fas t enough for the general needs of soil salinity assessment (Rhoades et a1 1999b) Only ER and been adapted for the georeferenced measuremen t of EC at and larger (Rhoades et aL 1999ab)

SOIL-RELATED (EDAPlflC) FACTORS INFLUENCING THE EC MEASUREMENT

The earliest field applications of geophysical measurements of Eshysoil science involved the determination of salinity through the soil of arid zone soils (Cameron et aL 1981 Corwin and Rhoades 1982 de Jong et aL 1979 Halvorson and Rhoades 1976 Rhoades and 1981 Rhoades and Halvorson 1977 Williams and Baker 1982) it became apparent that the measurement of Ee in the field to infer salinity was more complicated than initially anticipated due to the plexity of current flow pathways arising from the complex interaction the conductiv properties influencing the Ca measurements and Irl the spatial heterogeneity of those conductive properties

The in terp retation of ECa measurement is not trivial because f complexity of current flow in the bulk soi l Numerous EC tudies lull been conducted that have revealed the site specificity and complexity geospatial ECn measurements with respect to the particula r propert properties influencing the ECn measurement at the study site able 1 (taken from Corwin and Lesch 2005a) is a compilation of ECn studie~

the associated dominant soil property or properties measured b EC it each study

The advantages of the ECn measuremen t are that it is rapid reliable ) easy to take which have made it an ideal field measur ment tool Ho ever because of the multiple pathways of conductance it is often diHk to interpret orwin and Lesch (2003) provided guidelines f r the U t

ECn in agriculture by identifying the complexities of the ECI1 measurel1~nt

LAB RATORY AND FI ELD MEA

10-1 Compilation of Literature M ~ bull L_ _ __ l _ ~ JC

313

CTNG THE

s vial becillls I I tl lS EC stud i s h and c mpl it iCUlar prup rh r d si tL Tabk of C studilS nJ~asur d b l r

apid re lib l n lent t)( I 110

it is o ften Jiffi llt es fel f lh lImiddot f

Ee mea U rlml~111

LABORATORY AND FIELD MEASUREMENTS

1I Compilation of Literature Measuring ECn Categorized Jmg to the Physicochemical and Soil-Related Properties

Iither Directly or Indirectly Measured by ECG

References

1 J urjd Svil Properties

Halvorson and Rhoades (1976) Rhoades et al (1976) Rhoades and Halvorson (1977) de Jong t aL (1979) Cameron et aL (1981) Rhoades and

Corwin (1981 1990) Corwin and Rhoades (1982 1984) Williams and Baker (1982) Greenhouse and Slaine (1983) van der Lelij (1983) Wollenhaupt et aL (1986) Williams and Hoey (1987) Corwin and Rhoades (1990) Rhoades et aL (1989b 1990 1999a 1999b) la ich and Petterson (1990) Diaz and Herrero (1992) Hendrickx et al (1992) Lesch et aL (1992 1995a 1995b 1998) Rhoades (1992 1993) Cannon et al (1994) Nettleton et aL (1994) Bennett and Ceorge (1995) Drommerhausen eet al (1995) Ranjan et aL (1995) Hanson and Kaita (1997) Johnston et aI (1997) Mankin et aL (1997) Eigenberg et aL (1998 2002) Eigenberg and Nienaber (1998 19992001) Mankin and Karthikeyan (2002) Herrero et al (2003) Paine (2003) Kaffka et aL (2005) Lesch et aI (2005) Sudduth et al (2005)

Fitterman and Stewart (1986) Kean et aL (1987) Kachanoski et aL (1988 1990) Vaughan et aL (1995) Sheets and Hendrickx (1195) Hanson and Kaita (1997) Khakural et al (1998) Morgan et a1 (2000) Freeland et aL (2001) Brevik and Fenton (2002) Wilson et a1 (2002) Farailani et aL (2005) Kaffka et a1 (2005) Lesch et aL (2005) Sudduth et al (2005)

bullmiddotrellted Williams and Hoey (1987) Brus et al (1992) nd clay depth Jaynes et aL (1993) Stroh et aL (1993) Sudduth

pan or sand layers) and Kitchen (1993) Doolittle ct al (1994 2002) Kitchen et al (1996) Banton et all (1997) Boettinger e t aL (1997) Rhoades et aL (1999b) Scanlon et al (1999) Inman et a1 (2001) Triantafilis et aL (2001) Anderson-Cook et aL (2002) Brevik and Fenton (2002) Lesch et aL (2005) Sudduth et aL (2005) Triantafilis and Lesch (2005)

urnity-rela ted Rhoades et aL (1999b) Gorucu et aL (2001) ornplCtion)

(contillued)

314 AGRICULTURAL SALI ITY ASSESSMENT AND MANAGEMENT

TABLE 10-1 Compilation of Literature Measuring ECn C tegorizld F ccording to the Physicochemical and oil-Rela ted Proper ties either Directly or Indirectly Measured by ECIl (Contillued)

Soil Property References

Indirectly Measured Soil ProplTHes

Organic matter -related Greenhouse and Slaine (1983 1986) Brllneampl~ (including soil organic Doolittle (1990) yquis t nd Blair (1 99 1) IAI

carbon and organic (1996) Benson t al (1997) Bowling et ai (lOll chemical plumes) Brune et al (1999) Nobes et al (2000) FJrah1

et al (2005) Sudduth et al (2005)

Cation exchange capacity McBride et al (1990) Triantafi lis et al (2002) Fara h ni et al (2005) Sudduth et al (2005)

Leaching Sia ich and Petterson (1990) Corwin et al (ltr-shyRhoa des tal (1999b) Lesch et al (2005)

Groundwater recharge Cook and Ki lty (1992) C ok e t al (1992) Salall et al (1994)

Herbicide pJrtition Jaynes et al (1lt)lt)5) coefficients

Soil ma p unit boundaries Fenton and Lauterbach (1999) Stroh et aL (2001

Corn rootworm distributions Ellsbury et al (1999)

Soil drainage classes Kravchenko et al (2002)

From Corwin and Letich (2005a) with pl2rmis~i()n from Elsev ier

qu I1tl and how to deal with them As shown in Fig 10-8 three parallel pathwJI J fa t of current flow contribute to the EC meaSlllement (1) a liquid phJS paIr Intrpl w ay (Pa thway 1) via salts contained in th soil wa ter occup ying the iar It b pores (2) a solid pathway (Pathway 2) via soil particles that are in dirt (lmd lll

and continuous contact with one ano ther and (3) a solid-liq uid pathll 4 prcti n~ (Pathway 3) primarily via exch angeable cations associated with clay mil unm erals (Rhoade e t ai 1999b) To measure soil salinity the EC of only thelll irlfiu I solution (Pathway 1) is requir ed consequently ECa measures more til pr -tali just soil salinity In fact Cn is a measure of anything conductive witli~ mla~u

the volume of measurement and is influenced wheth r directly or indishy mflue rectly by any edaphic properties that affect bulk soil conductance nwnt

Because of the pathways of conductance EC is influen ed by a com sampli plex interacbon of edaphic properties including salinity tex ture (or satumiddot (xtents ra tion percentage SP) water conten t bulk densi ty (praquo organic malt plrticu (OM) cation exchange capacity (CEC) clay mineralogy and temperatufc lrtics () The SP and Pb are both directly influenced by clay content (or tex ture) an ing ltt o urthermore the exchange sLtrfaces on clays and OM prolide in~ ur solid-liquid phase pathway primar ily via exchangeable c lions con~I )ral i

In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I

Me in dir lid pllh th clin nlln

nlv th 011

~ mor tho n ti l ilh

LABORATORY AND FIELD MEASUREM ENTS 315

Pathways of Electrical Conductance Soil Cross Section

- 111 I

Solid Liquid Air

Scizematic howing the three conductance pathways of apparent

11 11(

Ilfp~

I1C~ E at th

lire

mity

rl II Icol1ductivity (poundCn) Pathway 1 = liqllid phase conductance Pathshy1 iii phase cOllductance and Pathway 3 = solid-liquid phase conducshy

1111 Rhoades et al (I989b) Reprinted with permissioll from the Soil Scishy II (If America

Jay type and content (or texture) CEC and OM are recognized inA uencing Ca measurements Measurements of ECII 11lISt be

retld with th se influencing fac tors in mind ramount importance that the concept of parallel pathways of

([111(( is understood in order to in terpret Ee measurements Intershy FL measurements is accomplished be t w ith gr und-truth measshytnt~ of the soil physical and chemical properties that potentially

point of mea urement An und r tanding and intershy1 mof geospatial ECn data can only be obta ined from ground-truth

llf soil properties that correlate with ECa from either a direct ~nre or indirect associab n For this reason geospatial Ee a measureshy1 I re lIsed as a surrog t of soil spa tial variability to direct soil rlm~ when mapping soil salinity at field scales and larger spatial nl TIley are not gen rally used as a dLrect measure of soil salinity 1llarlyat E 1 lt 2 dS m- I where the influence of conductive soil propshyoth r than salinity can have an increased influence on the EC readshyt high EC valu salini ty is most Likely dominating the EC readshy11netjUently geo p a tial ECa measurem nts are most likely mapping

p

316 AGRICULTURAL SALINITY ASSESSME NT AND MANAGEMEI T

METHODS OF FIELD-SCALE SOIL SALINITY MEASUREMENT

Soil salinity is a dynamic soil property that is highly spatiall) temporally variable The dynamic nature of soil salinity makes mapF and monitoring of alinity a difficult challenge Mapping and m In

ing soil salLnity at Geld cale requires a rapid reliab le easy metht taking geospatia l measurements The us of soil samples to m (Jshy

salinity (eg ECCI ECl ECu Ee l s or ECp) at field scales is imprdl b cau e of the need for hundred nd even thousands of grid samThe u e of soil samples to measure alinity at field scales is only pn cal when sampling is di rected to minimize the number of samplt I

refl ect the range and variabili ty of salinity within the area of study n can be achieved usi ng easily measured spatial informa tion correlatlgtd soil salinity as a means of direc ting where to take the fewest silmF Two poten tial sources of correlated spatial informa tion used to dir where soi l samples should be taken to measure ECr are (1) visual observation and (2) geospatial measurements of ECn with mobile ER EMI equipment

Associated with visual crop observa tion but considered a distrr poten tial app roach is the use of multi- and hyperspectral imagery EI though the lise of remote imagery has tremendous potential at this p it is still restricted to research because the methodology has not bl

developed for general application to mapping and monitoring salinit present only the use of geospatial measurements of ECn can provide fbJ

abl accurate maps of salinity at field scales Even so remote ima~~ willlmquestionably playa fu ture role in mapping salini ty particul rl landscape scales

Visual Crop Observation

Visual crop observation is a quick method but it has the disadvanta~

that salinity development is d etected after crop dama ge ha OCCl1m~

consequently crop yield mus t be sacr ificed to locate areas of salinit development Furthermore decreases in crop yield are not necessari the consequence of only salt accumulation rops respond to a vari~1

of anthropogenic (eg irrigation uni formity farm equipment traifil edaphic (eg salinity water content texture OM) biological (eg dl~

ease nematodes) meteorological (eg precipitation humidity temper ture) and topographical (~ g slop elevation microrelief) factors an of which can cause yield reduction Because of the variety of fac tor influencing crop yield and qua li ty the use of visual crop observations assess soil salinity is not definitive and can be extremely misleading

The least desirable method to measure salinity disbibution in the fi I is visual observation because crop yields ar reduced to ob tain soil sa lirmiddot

ospat

HIcl l1

rnLllh oi li~o lila nl nt

nn ln l

Ialld wit 1111 pting

Thilt iI pi 1I~ld SI11

ppliCJ til nllnt unil lTlln t-md

l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn

11 ctrit fm field -~

Jilr~e wh u) patl I lobie E(

( - nlllln (

Il1Q1 Kit 1 11 mobi le Il maph ur lmcnt olpproachc

317 ND IvlANAGflvlFNT

ry MEASUREM ENT

It is highly sF1 a tia lh I

middot1 r 5 nhlppl sa Ill i t~ ma k MapPing and munih r~Iiable easy m thpd ~d samples to nWd ur Ield sca les is imprltI lI~ usands o f grid sump ~Id cales is on l pnlh lu mber of sampllgt In 1 the area of stud- n formation Corr la lldl ke t~E fe west sa nlpl rmatIOn Llsed tll d ir EC Clr~ (1) vi ua l rnp ECa WI th mobil I R or

cons id ered a d is till t

pectral im ger) I lTl

P t ntial a t th is p lint gtd ology has nllt bel 11 0n itoring S lin il Ee

an providl rell 1 ~O rem o te imlgl lhnrty p rticu liJrh1

as the disadvan tt1~ nage has occu rred te a r s of sa li nit are no t n C sSlnh Spond to a aril t quipment tr ai l ) lololtgtical ( g J

bull f Imiddot

un id ity templmiddotrl treE) facto am variety E fa hIp

p bservati ns til I mi leadin

n JOons in th e fidd obtain soil s)lill-

LAB RATORY AND FIELD MEAS UREM ENTS

rmntion and the crop yield decrements may or mClY not be related ih However remote imagery is increa ingly becoming a p art of

ture and poten tia lly represen ts a quantitative approach to visuCll tion Remote imagery may offer a potentia1 for e rly detection of middott of salinity damage to p lClnt The expectations for the use of

and hyperspectral magery to map and monitor soil salinity as well p~ ba l variabili ty of other soil properti e (eg w ater content minshyund others) is high and will no doubt prove fruitful as research

Il in thi area

patialECa Measurements

JU ( of the quickne ~s and ease with which geospatial measureshyot EC can b obtained and beca u e ECn 111 asures a variety of p ropshyulatpotentiall in fluen ce crop yield and quality (ie salinity water tex ture OM bulk den i ty) geospa tial ECa measuremen ts can 1 1 surrogltlte to charact rize the spatial variability of a variety of rtie particularly soil salinity (Corwin 2005) It has been hypotheshy

th Corwin and Lesch (2003 200Sb) tha t spatial Ee information can i to develo a soil sampling p1an that identifies sites reflecting the

l dnd variability of soil salinity and or other soil properties c rreshyh ith ECabull The use of geospatia l EC measurements to direct a soil rung plan is ref ned to as EC-directed s il silmpling (Corwin 2005) lpprnilch 11 been dem nstra ted for not only mapping salinity at

Ldl (Corwin e t al 2003a Corw in and Lesch 200Sc) but also for hJ tions in (1) precision agriculture to define site-spM e manage-n uniL ( orwin 2005 Corwin et al 2003b) (2) m lutoring manageshyIlnd uced spatia-temporal change due to d egrad ed water re use 10 et al 2006) (3) characteriz ing soil spCltial a riabi1ity (Corwin

bull gtmd (4) modelin nonpoint source p Ilutants in the vadose zone ~in 2005 COloin et al 1999) aeh of thes applications uses ECnshy

ild soil sampling to chara teliz e the spatial variability of a soil p ropshylr properties of significance to the p articular application

1 lrical resisti ity (eg Wenner array) and EMI are both well suited Illld-scale applications because the ir volumes of m aSllrement are _ which reduces the influence of local-scale variability To obtain f1Iii11measurements a mobil means of measuring ECa is e sential lltL equipment has been developed by a variety of researchers

nnon et al 1994 Cart ret al 1993 Freeland et aL 2002 Jaynes et al Itchen et al 1996 McNeill 1992 Rhoades 1993) The development

m(l~ il EC~ measurem en t equipm nt has made it p ssible to produce I maps with measur ments taken very few met rs Mobile ECI measshy

rncnt equipment has been developed for both ER and EVl1 geophysical rroldlcs

(al

tud demor I lIl l11 nl

hll h w~rra

ui l ample

FICURE 10-9 Mobile appare11t soil electrical conductivity (EC ) eq ltipn III soi l l-l (a) Veris 3100 electrical resis tivity rig and (b) electromagnetic illdllctimiddot II properti developed at the US Salinity Laboratory with n close-up of the sled cOll tain II Il1t1t i n dual-dipole Ceonics EM-38 dl tilln-ba c

318 AGRICULTURAL SALINITY ASSESSM ENT AN MA AGEME IT

By mounting the fo ur ER lectrodes to fix their spacing consid~r

time for a measu rement is aved A trac tor-mounted version of th electrode array has been developed that georeference the Eemment with a CPS (Rhoades 1993) The mobi le fixed-electrodemiddotr equipment is well suited for collecting d tailed maps of the spatial ability of C~ at field scales and larger Veris Technologies (20 11 developed a commercial mobile system for measuring ECu llsing thl ciples of ER which uses the spacing of 6 coulter electrode to measure to depths of 0-30 and 0-91 em (Fig 1O-9a)

e

IMlORATORY AND FIELD MEASUREMENTS 319

l1I equipment clevel p ed at the US Salin i ty Laboratory IllY]) is availabl for app raisal of soil salin ity and other soil

I g water content and clay content) using an EM-38 h~ mobile Ml equipment developed at the Us Salinity Labshy

m(ldified by the addi tion of a dual-dipole M-38 unit (Fig d D EM-2 Th d ual-d ipole EM-38 conductivity meter

_ U IV records data in both dipole orientations (horizontal and dl tlme intervals of just a few seconds between readings The

11 equ ipment is suited for the detailed mapping of EC(I and oil properties at specified depth inter als through ti le rootshyJUIantage of the mobile d ual-dipole EM equipment over the lJ-array resistivity equipment is that the EMI technique is so it can be used in dry frozen or stony soils that w ould

t1dble to the invasive technique of the fi xed-array approach neld for good elec trode-soil contact Th disadvantage of the

fl)11h would b tha t the ECn is a depth-weighted value that i wIth depth McNeill (1980)

I Jt the Salinity Laboratory have developed an integrated Ir th measurement of field-scale salinity consisting of (1) mobile

J ur ment equipment (Rhoades 1993) (2) protocols for ECnshy

jJ ampling (Corwin and Lesch 2005b) and (3) sample design Ilt~ch et al 2000) The integrated system for mapping soil salinshy

maLicil lly illustrated in Figme 10-10 rwtncols of an C I survey for measuring soil salinity at field scale

li hi basic elements (1) ECn survey design (2) georeferenced ECn

III lion (3) soil sampl design based on georeferenced EC data nlple collection (5) physical and chemical analysis of pertinent

ptrties (6) spa tia l s ta tis tica l analys is (7) determjnation of the nlij properbes influencing the ECa measuremen ts at the tudy

md (R) GIS development The basic steps for each element are proshymTable 10-2 A detailed discussion of the protocols can be found in nJnd Lesch (2005b) Corwin and Lesch (2005c) provide a case Jlmonstrating the use of the protocols Arguably the most signjfishy

mtnt of the protocols is the ECn-directed soil sampling design mmts discussion

ample Design Based on GeospatiaJ ECn Data

l a georeferenced ECn survey is conducted the data are used to h the locations of the soil core sample sites for (1) ca Ubration of li l silmple ECe and or (2) delineation of the spatial d is tribution of

t lprties correla ted to ECa within the field surveyed To establish Jtillns where soil cores are to be tak n either design-based or preshytmiddotba~ed (ie model-ba ed) sampling schemes can be used D signshy

320 AGRI ULTURAL SALINITY ASSESSMENT AND MANtGEiYfIT

ECa Survey

Sample design

FIGURE 10-10 Schlmatic of the integrated system for lIlilppillgficd- ~

salinity as developed at the US Salil1ity Laboratory

Map of Salinity

Response surface IIIIIIIt~

bull Basic statistics _--1- Simple statistical correlalkn

bull F-tests bull Graphical displays etc

b

b 11

based sampling schemes have historically been the most commClnl~ 0

and h ence are more famHiar to most research -cien tists An e Cl I l

review of design-based methods can be found in Thompson (1 lu Design-based methods include simple random sampling str tifi J dom sampling multistage sampling cluster sampling and n twork pIing schemes The use of unsupervised classification by Fraisse l

(2001) and Johnson et al (2001) is an example of design-based samr Prediction-based sampling schem s are less common although ~ I

cant statistical research has been recently performed in this area (V rali tal 2000) Prediction-based sampling approaches have been appli~ ll

the optimal coUec tion of spatial data by MiW (2001) the specificatio J 1 optimal de igns for variogram estimation by Miiller and Zimm in (1999) the estimation of spatially referenced linear regression mod ~il

Lesch (2005) and Lesch et al (1995b) and the estim ation of gell tati ~ b Dmiddot mixed linear models by Zhu and Stein (2006) Conceptually similar hshy Elt of nonrandom sampling designs for variogram estimation have llt mtroduced by Boga Tt and Russo (1999) Russo (1984) and Warrick Myers (1987) Both design-based and prediction-based samp ling melhl can be applied to geospatial EC d ata to direct soil sampling as a mean

IltJ tcharacterizing soil spatial variabili ty (Corwin and Lesch 200Sb)

I~ b n ri k nd mlthod n Ciln 01

LIAOIltATORY AND FIELD MEASUREMENTS

Ill- Outline of Steps to Conduct an EC Field Survey to Soil Sa

plioll and ECn survey design rd -i tl metadata

me tht projectssurveys objective bli-h ite boundaries t rs coordinate system

hli h F measurement in tensity

coJle tiOIl with mobile CPS-based equipment

321

rdlfnc( site boundaries and significant physical geographic lure with CPS NJrl georeferenced ECn data at the predetermined spatial

ten-ity and record associated metadata

pie design based on georeferenced ECn data tdica llyanalyz EC da ta using an appropriate statistical

mphng design to establish the soil sampie site locations tJbliJhsite location depth of sampling sample depth increshy11t and number of cores per site

rt mpling at specifi d sites designated by the sample design ittlin measurements of soil temperature through the profile at I Ild sites t r~ndomly seJected locations ob tain duplicate soil cores within

J f-m distanc of one another t estabIish local-scale variahon of II properties

fi(wd soil core observations (eg mottling horizonation texshyurlldiscon tin ui ties)

1[HOfY analysis of soil salinity and other ECn-correlated physical chemical properties defined by project objectives

oded stochastic andor deterministic calibration of EC to ECe or thef ~ il properties (eg water content and texture)

[IJ I statistical analysis to determine the soil properties influencing

rlriorm a basic statistical analysis of physical and chemical data In luding soil salinity by depth increment and by composite Jpth over the depth of measurement of ECa

[ termine the correlation beh-veen EC and salinity and between EC ilnd other soil properties by composite depth over the depth III measurement of ECw

Jatabase development and graphic display of spatial distribution I iI properties

Inlln Corwin and Lesch (2005b) specifically for mapping soil salinity

322 AGRICU LTURAL SALI NI TY ASSESSMENT AND MANAGEMElT

The p rediction-based sampling approach was introduced b I et al (1995b) This sampling approach attempts to optimize the of a regression modet tha t is minimize the mean squaT predic iOIl produced by the calibra tion function while simultaneously ensll rin~

the independent regression model residual error assump tion approximately valid Th is in turn allows an ordinary regression be used to predict soil property levels at all remaining (i e conductivity su rvey sites The basis for this samp ling approach di rectly from tradi tional response-surface sampiing methodolog and Draper 1987)

Ther are two main advantages to the response- urface approach a substantia l reduction in the numb r of sampl required for estirne ting a calibra tion function can be achieved in comparison tll traditional design-based sampling schemes Second this approach itself natura lly to the analysis of Ee data Indeed many typ of airborne- and or satellite-bas d remotely sensed data ar often p cifically because one expects these data to cor re late strongl

some parameter of interest (eg crop s tr S5 soil type soil 5alinilll the xact parameter estimates (associated with the calibration may still need to be determined via some type of s ite-specific design The response-surface approach explicitly optimizes this sit tion process

A user-friendly software package (ESAP) develop d b Lesch (2000) w hich uses a response-surface sampling d ign h proven particularly effective in delinea ting spatial distribution of s il from EC survey data (Corwin 2005 Corwin et a1 2003ab2006 and Lesch 2003 2005c) The ESAP software pack ge id ntifies tht locations for soil sample sites from the Ee survey data These si tl selected bas d on spatial statistics to reflect the observed spatial ity in Eea survey measuremen ts Gener lly 6 to 20 sites are depending on the level of variability of the ECn measurements for a The optimal locations of a minimal subset of EC17 survey ites Me middot

fied to obtain soil amples Once the number and location of the sample sites have been

lished the dep th of soil core sampling sample depth increment number of sites where duplicate or r p licate core samp les hould be are established The depth of sampling should be the Sam at each site and should extend over the depth of penetr tion by th ment equipment us d For instance the Ge nics EM-38 measure dep th of roughly 075 to 10 m in the horizontal coil configura tion ( and 12 15 m in the vertical coil conf igura tion (EM) Sam ple depth men ts clre flexible and depend to a great ex tent on th study objecti depth in rement of 03 m has been commonly used at the us Laboratory because it provides sufficient soil profile information OLmiddotr

LABORATORY AND FIELD MEA5UREMEI T5 323

U~sectlW_12 to l5 m) for statistical analysis without an 0 erly burdenshyaU(~Iftllnlh(r of sample to conduct physical and chemical analyses Lnmullrcments should be the ame from one sample site to the next ~1lItIlI1lblr nf duplica tes or replica tes taken at each sample site is detershy

tllhllJrIIJ_1II the desired accuracy for characterizing soil properties and the tablishing th level of local-scale variability at the site Duplishy

are not necessarily needed at every sample site to estabshybullbullbulllGhUlU variability

bull tli6mlionswhen Conducting an ECIT Survey

when conducting a urvcy to map soil salinity Each of these considerations

1IIiUtnct the e measurement leading to a pot ntial misinterpretashyibI ldlir ity dL tribution TIlese consid rations account for temposhy

~un surfac roughness and surface geometry effects lraJcompa risons of ge spatial EC measurements to determine

pornl changes in salinity patterns of distribution can only be mE survey data that have been obtained under similar watershynJ Itmperature conditions Surveys of Een should be conducted 1 iller content is at or near field capacity and the soil profile temshydrt similar For irrigated fields ECII surveys should be conshy

I ughly two to four days after an irrigation or longer if the soil is In content and additional time is needed for the soil to drain to

FJl1tv For dryland farming the sUIvey should occur two to four J substantial rainfall or longer depending on soil texture The

IlLmperature can be addressed by tak ing soil profile temperashylhllime of the ECa SUrY y and tempera tu re-correcting the ECn

I_ nl~ or by conducting the surveys roughly at the same time durshy Jf() that the temp ra tur profiles are the same for each survey pe of irrigation used can infl uen ce the within-field spatial distrishyIt 1 ter content and should be kept in mind as a factor influencshy

patial patterns Sprinkler irrigation has a high level of applicashylormity wh rea flood irrigation and drip irrigation are highly

~~11ll1111I In genlral poundIood irrigation results in higher water contents at the head end of the field while underleaching and

Jt~r ((lntents can occur at the tail end of the field This general 1l-m-I1tJO trend is observed for both flood irrigation with basins

i Irrigation with beds and fm rows bu t beds and furrows intro-III Jdded level of localiz d complexity Flood irrigation with beds

rt1~ r lilts in localized variations in water content with high nllnts and greater leaching occurring under the furrows while

lin ll III 1 rically show lower wa ter con tents and accumulations of r the

bull bull

324 AGRICULTURAL SALI NITY ASSESSME NT AND MANAG EM ENl

The presence or absence of beds and furrows is a significant factI ing a geospatial EC survey Measurements taken in furrows I I ill from measuremen ts taken in beds due to water flow and salt ililU

tion patterns In addition the physical p resence of the bed infl ut1lI conductiv ity pathways parhcula rly when using EM These geometry effects are in addition to the effects of moisture and sallmt tribution patterns that are present in beds and furrows To asses I

in a bed-fu rrow irrigated field it is probably best to take the EC urements in the bed Above all the Ee measurements must be con Ishyeither entirely in the furrow or entirely in the bed bullSurveys of drip-i rrigated fi elds are even more complicated than surveys of bed-furrow irrigated fields Drip irrigation produces (ltm

local- and field-scale three-dimensional patterns o f water content salin ity that are particularly difficult to spatially characteriz~

geospatiaI ECo measurements (or any salinjty measurement technique that matter) The easiest approach is to run EC transects both OIW

between drip lines to capture the local-scale variation The roughn 5S of the soil surface can also influence spatial Eem

urements Geospatial EC measurements taken on a smooth field ur will be higher than the same fi eld with a rough surface from diskin~ l

is due to the fact that the disturbed disked soil acts as an insulated lac the conductance pathways thereby reducing its conductance Whtl1C ducting a geospatial E a survey of a field the entire field must ha ~ same surface roughness

EC

These factors if not taken into account when cond ucting an E vey will likely produce a banding effect For example if an Eeampun is conducted on a field that has areal differences in water content s ilp file temperature surface rouglme and surface geometry then band

I I such as those found in Fig 10-11 will resul t These bands reflect variations in soil moisture temperature roughness and surface gell try which must be uniform across a field to produce a reliable EC un

that can be used to djrect soil sampling to spatially characterize the dt bution of salinity

USE OF REMOTE IMAGERY FOR M EASURING SOI L SALINITYAl FIELD AND LANDSCAPE SCALES

While field-based measurements of soil salinity ha e progr ~ _ greatly over the past decades they rema in limited to mapping soil salin i~

over a small number of fields in a single day Assessments of soil sa lin across entire landscapes and through time are therefore difficult al1t expensi e to conduct with field-based approaches alone R note sens instruments aboard airplanes or satelli tes routinely acquire mea5un

I

325 l-IANA [MEN T

significa n t fKIt r dur in fu rrows 111 Lilt fV and salt J mul he bed infl uL11 EMJ Th esl ur

)rnpli ated lhlO I ~ eoduc So t rnpl t wat r con t nl md

charac te rize II ~ment techniqu r sects both () r nd

e spatial EC I

mooth fi ld uri ~ from d isking I

In insulattd l ltl~ lr I uc tanc When ron field must hw h

lucting an Ee ur Ie if an Eebull lin

~r cant n t Sllj prl e try th n band (I

bands ref oct th nd surface gCtlrnC

eliablc E SlIn racter ize the di tn

IL SALINITY AT

have prog rc d pping oi l alinit nts f soil s linih ore di fficul t an t Rem t gtensin) lcquire measurtshy

LABORATORY AND FIEL D MEASUREM NTS

[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410

URi [(J-IJ A poorly designed apparent soil electrical conductivity (EC) ~hlwil1g tile banding that occurs when surveys are conducted at different

IIIIJII varyil1g water COil tents temperatures surface roughnesses and surshy1IItlry cOl1ditions

n~ llf energy r fleeted or emitted from the land surface across wide tn~ of land thus pr en ting an opportunity for low-cost mapping of nlty at broad scales l nirtunately in our estima tion efforts to relate remote sensing data

Iii ill inity have aebie ed limited succes Most methods ha v b en nIl tmpirical in nature and empirical relationships su cessfuJ in one

ha re tended to break down when applied to data from different

326 AGRICULTURAL SALINITY ASSESSM ENT AND MA NAGE lENT

scales years or locations his is especially true in the case of map salinity at slight to moderat levels (ECc = 2 to 8 dS m - I

) Herc we vide a selective review of past work and highlight t he approadw believe are most promising for the future More exhaustive rc itll remote sensing techniques fo r soil sa lin ity can be found il M ttem

and Zinck (2003) and Mougenot et a l (1993) As with EC remote sensing measurements are influenced by a ra

of land surface proper tie with soil salinity [epres n ting nly one ofll facto rs The overall challenge is to find some measure that is sensltil soil salinity but insen itive to other factors that vary in [he landscaptmiddot measure may be r flectance or emittance at a particular wavelength strategic combination of measurements made a t d iffe rent wa I n~t dat s or locations Importantly the appropriate measure may d ptgtnd the aspect of 5 il salinity that is of interes t For examp le reflectan tlr a soil surfac is affected by salinity only in the upper few centimett soil which may not be representative of average sa linity at grr depths In contrast reflectance from plant canopies can provide inflrJ tion on soil salinity throughout th rootzone

M uch of the work on remote sensing of salini ty has been done irt I two m jor agricultural regions affected by s lini ty the irrigated terns of India and Pakistan and the rain-fed systems of Australia bull work re lied heavily on visual interpre tation of aerial p ho tos or LJnd satellite images Verma et al (1994) observed that r mote indicatorshycanop y biomass [Landsat red and near-infrared (NlR) reflec tancci ll ing the peak of the cropping season in the Indo-Gangetic Plain cessfull y distinguished barren saline soils from healthy CIOP land r 1I

Landsat thermal image was then used to separate saline fields fromI

low fields with sandy oils which had similarly bright reflectance mlS

ues but lower soil moisture Ie el s Many similar stud ies have been ( 1 Ihl ducted through u t In d ia tha t rely mainly on a lack of vegetation salt-affected soils (JDNP 2002 Sharma et al 2000) Other studib h1 u sed images acquired prior to the growing season when whitemiddot crusts on the surface of saline soils are significantly brighter than nl saline soils (IDNP 2002)

Both of these approaches can be quite useful for m apping sem saline soils (BC gt 25 dS m - I ) but are problematic for less se ere cases tl are not marked by sal t crusts and barren land In general an important t tor in evaluating any study is the range of salinity values ampled F examp le a high model R2 can be dTiven by a few points above 20 dS n even though the models predictive power a lower levels is poor

The more challenging problem of mapping slight to moderate sa liru rc luil has been approached in several ways A common method has been to nil the health of (JOp condition as n indicator of soil salinity In aerial ph(11 It il

327 LABORATORY AND FIE D MEASUREM ENTS

I Iur infrared film dense vegetation appears brigh t red saline 111 bright white and fields with sparse canopies appear p inkish Iral ~akllite data can be similarly disp layed and interpreted

Mlln qUclOtitative measures can also be used such as the normalshyr n I vegetation index (NDVI) bas d on NIR and r d reflectance

IR Red) (NIR + Red) mple Wiegand et al (1994 1996) found strong linear relation-

hllen NDvr and rootz one salinity in salt-affected cotton and fie lds Howev r such simple relationships are only likely to I~ where sa linity is th major factor responsible for variability IdJ Landscapes with only slight to moderate salinity are like ly mtn other fac tors such as field management that affect yields 1r m re than salini ty Extrapolation of relationships within a

umblr of salt-affected fields to an entire landscape can therefore large errors

dUM this problem some have proposed llsing average crop II I r a number of years to filter out n oi e from nonsoil factors

1 II Vlt1ry from year to year Lobell et al (2007) found very w e k hip~ behveen salinity and yields in individuaJ yea r in the Colshy

Rllcr delta region of Mexico but much stronger correspondence 11 lli nity and maximum yield over a six-year period In Australia d JI (1995) r ported large commission er rors fo r a classification of It when lIsing a single year of image d ata because many areas ropcondition were incorr ctly labeled as saline These errors of

ion were reduced from 20 to 2 by the add ition of a second Iwndsat data lh~ r (Ommlln approach is to estimate salinity from soil reflectance

ilne I Ired when th surface is bare These methods rely on the bright Itell ~ I retlectance of smface salts several characteristic absorption feashyatic n ln Jt longer wavelengths or both (Ben-Dar et a1 2002 Csillag et al is h1 ldUtlfl and Taylor 2002) H owever because soil refl ctance can h il l lit tly due to spatially and temporally va riable moisture or surshyIa n 011- llghness conditions these techniques often result in p oor accurashy

lTI applied outside of th e calibration dataset As mentioned soil l middotir I oJ t the surface can also correlate poorly with average r otzone ls~ Ih t It tlIl t ( shy I~-developed bu t promis ing approach is to exploit the spatial Ild f ( IT I1ion of remote senSlltg da ta Because salts tend to be spatially helshyjSm I us sa line fi elds may be identified by a high standard deviation

01 witbin fields (Metternicht and Zinck 1997) This approach i1 in it lr relatively high spatial re olution imagery accurate information I to 1I bull middotId boundaries and a relatively low contribution of o ther factors to p hotll mmiddotfield heterogeneity

328 AGRICULTURAL SALI NITY ASSESSME T AND MA NAGEM[ij

Overall no single remote sensing approach has proven parti effective for mapping salinity at low to moderate 1 v Thertttl most successful approaches are likely to combine information fr mJ ety of sources including multiple rem ote sensing measmes as wlll eral nonremote indicators such as landscape position soil t~ p~

topography (Furby et at 1995 Mettem icht 2001 Tweed et aL 2rMr with any spatial p rediction problem the use of ind ependent validlt data will also be critical to evaluating and improving salinit e tin For example simply extrapolating local empirical relationship 1

mate regional tota ls (Madrigal et a1 2003) should be avoided A F et a1 (1995) demonstrate reserving a Significant fraction (in their half) of sites for ind pendent validation can help to identify shortconl~

in the original algorithms and sugges t improvements Another IInpo~ methodological consideration for regional mappiI1g is thatites houl selected at random and not preferentially in saline areas able 10- ents a summary of elements that are most Hkely in our opinion to rl in successful salinity mapping with remote sensing a t landscape Recently LobeU et a1 (2010) p ublished a successful regional-scale ~alm asses ment of 284000 ha using these recommend d elements

TABLE 10-3 Some Elements K y to Successful Remote Sensing of Salinity at Landscape Scales

Element Comment

VVeU-timedimage Images should be selected if possihl acquisition from end of dry sea on for method~

based on soil reflectance or from pea of growing season for methods ba cd on crop canopy reflectance

Randomly selec ted A bias of training sites toward highshytraining sites salinity fields will likely re ult in an

overe tima tion of regiona l salinity levels

Independen t validation data Prediction errors for test data can be much larger than training errors

Multiple years of images Nonsoil factors can heavily influence reflectance in anyone year but will tend to average out over multiple years

Ancillary data Combining remote sensing with the GIS data ( oil texture topography etc can greatly improve model accu racy

-

bull hill prl( Iii bull mpl

bull I hI use 0

If d ive i

tnltiur n rninimil

bull I hI amp Ir are

11 L ofie bull Icaurc

l JSld on nd lime Ie it i Ill l l ~c t ri fItmiddotctcd m lter i oi l rem)

bull illr field pIing IF oil r 111 so il cncegt 0

or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l

The lechl tth EC-d prt)(ol is (

RpoundFERENC

moozegarmiddot ccntra tio cnt diffu

329

if po sill m lthlld from I ds ba~ d

I

mill the number of 11

f ftdd conditions

Ilnll~d()main r

I m ~ erature

( -III IS outlined in Table 10-2

gdr-Filrd A U

I AIlUIVTORY AND FI ELD MEASUREMENTS

u methods of measuring estimating soil salinity have pros

pn -i~e and reliable directly measuring the aqueous extract of pit in the laboratory is labor-intensive and costly llf soil samples to measure salinity at field scales is only

t It if sampling is directed using an easy-to-take surrogate ufLmlnt such as apparent soil electrical conductivity (Eea) to

amples pllvolum s of soil solution extractors and soil salinity senshy

ft -mJl which affects their ability to provide data representashy

urtmcnts of apparent soil conductivity (Ee) can be made lln electrical resistivity (ER) electromagnetic induction (EMI)

fl ctome try (TDR) In general when measuring il l important to take into consideration the multiple pathways

I middottrieil l conductivity in the bulk soil consequently Bea may be lHi by salinity texture water content bulk density organic

Ilf in the soil cation exchange capacity clay mineralogy and

I1lld-scale salinity measurement a systematic Ben-directed samshyn appcoJch is required that minimizes the primary influences of property effects (such as water content texture bulk density

nJ Ilil temperature) and avoids the confounding secondary influshy(If soil condition effects (such as surface roughness presence

3~ nces of beds and furrows ambient air temperature effects on in trumentation and compaction) to reliably measure the target

11pcrty of soil salini ty bull tn1l1te sensing techniques are an experimental approach to mapshy

In) oil salinity over regional scales with tremendous potential but tier correlations between energy strength and spectrum and field

Inoitions are needed before the technique is reliable

ItCh nique for mea uring and mapping soil salinity at field scale directed soil sampling is well understood and an eight-step

ielsen D R and Warrick A W (1982) Soil solute conshylln distributions for spatially varying pore water velocities and apparshy

Jlifllsion coefficients Soil Sci Soc Am J 46 3-9

obit

ld-scalqt

s Bonrd H

330 AGRICULTURAL SALINITY ASSESSMENT AND MANAG UAE tl

Anderson- oak C M All y M M Roygard J K F Khosla R and Doolittle J A (2002) Differentiating soil types using electrom conductivity and crop yield maps Suil Sci Soc l lll1 J 66 1562-1570

Banton 0 Seguin M K and Cimon M A (1997) Mapping fi properties of soil with electrical resistivity Soil Sci Soc Am f 61 (4) Il l shy

Barnes H E (1952) Soil investigation employing a new method of 1lt11rmiddot determination for earth resistivity interpretation Highway e26-36

Ben-Dor E Patkin K Banin A and Kmnieli A (2002) Mappi ng oh~[f

properties using DAIS-79J 5 hyperspectral scanner da ta A case stud clayey soils in Israel Int J Remote Sen 231043-1062

Bennett D L and George R J (1995) Using the EM38 to measure the soil salinity on ucalyptus globllllls in south-w stern Australi Agr Mnuagc 27 69-86

Benson A K Payne K L and Stubben M A (1997) Mapping ~round contamina tion ll sing DC resistivity and VL F geophysical methods study Geophysics 62(1) 80-86

Bigga r J W and Nielsen D R (1976) Spatill variability of the l(aching tcris tics of a fitld soil Water csollr Res 12 78-84

Boettinger J L Doolittle J A West E Bork E W and Schupp L I I ondestructive assessment of rangeland soil depth to p troca ci( h using lectromagnetic induction Arid Soil es Rehabil 11(4) 372-3911

Bogaert P and Russo D (1999) Optimal spatial sampling design for UL mahon of the variogram based on a least squares ilpproach Water RfStlur 351275-1289

Bowling 5 D Schulte D D and Woldt W E (1997) A geophysical alld 1shytical methodology for evaluating potential sulrurfilce contaminatioll frolll 1ltllOff retention ponds ASAE Paper o 972087 1997 ASA Winter Ml III

December 1997 Chicago ASAE St Joseph Mich Box G E P and Draper R (1987) Empirical lodel-bllilding ami rcI~11I

fil ces John Wiley and Sons lew York Bres ler E McNea l B L and Carter D L (1982) Saline and sodie soils Sprir

Verlag ew York 174- 181 Brevik E c and Fenton T E (2002) 111e relative influence of oil wJtcr

temperature and carbonate min rals on soil electrica l condu ti vity rldU taken with an EM-38 along a Mollisol catena in central [owa Soil SlIrr 11 439- 13

Brune D E and Doolittle J (1990) Locating lagoon seepage with [dar electromagnetic survey Environ Geol Water Sci 16 195- 207

Brune D - Drapcho C M Radcliff D E HaNCr T and Zhang R (1999) tromagllctic sllrvey to rapidly tlS5f S water quality ill (gricllltllral (UI1ttrmiddothed~ Paper 0992176 ASAE 51 Joseph Mich

Brus D J Knotters M van Door molen W A van Kerneb ek P and Seeters R J M (1992) The use of electromagnetic measurem OIl of JPPlt soil electrical condu tivi ty to predict the boulder clay depth Ceodcrm 79-93

Burger H R (1992) Exploration geophysics of the shalow Sllbsulface PrentiC( I ~ Upper Saddle Riv r NJ

lor hl f c I AIJI l Rl lres~

pound1 D L (1 Ill ) F

lfI IWI U rwin D L InJin t m rmy in lIpp eds rwin D L 1ll1Jll ) i ]inc- odi

I1fwin D L 11 p ci si(l ~H71

_ (2005

lUI LllIIl)

_ (20051 (lt11 Cllnducl - (lOOSc

11conduct l on 1 D L

1)~m middot nt-in lircctld by

331 LABORATORY AND FIEL D MEASUREMENTS

Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO

g d ign fl r Ihl ~ I 1 Wallr 1~l oII R

ltysical (flld gpllt lIillatioll 11111 I 1 Winter Ml~till

ing ald I~ I(l1T ( II

sodic soif pring

of soil w C1t(r I Iduchv ity rlldll1

1 Soil C~ i 110

gc wi th ra r lIld )7

lng R (1 l)Q9) fI wlltersllds S f

btek p iUld n nents 0 1ppa rtlIt h ClodellIIi Ii

ICC Pr nU t HII

PR de Jong E Read D W L and Oos terveld M (1981) Mapping h Uimg resistivity and lectromagnetic inductive techniques Call J Soil

h7-78 I McKenzie R and Lachapelle G (1994) Soil-salinity mapping

htrom~g[1itic induction and sa tellite-based navigation methods Can 174(3)335-343

Rhoades J D and Chesson J H (1993) Mec1I711 ization ofsoil salinity nil fill moppillg A AE Paper N o 931557 1993 ASAE Winter Meehngs

I11Dtf 12middot-17 1993 hicago ASAE t Joseph M ich r l md Kilty (1 Y92) he licopter-borne elec tromagnetic survey to bull Jtq~roundwater recharge rates Water ResoUlmiddot Res 2 (ll) 2953-2961 I ( bull Walker C R Buselli C Potts 1 and Dodds A R (1992) T he I Jtiun of electromagne tic techniques to groundwater recha rge inves tigashy

I HIdral 130201-229 J) L (2002a) Solute conten t and conc tra tion-Mea urement of solute 111rdtilln usi ng soil water extract ion Suction cup in Methods of soil j flllrt 4 Phy iCflI methods J H Dane and G C Topp eds SSSA Book

o i SSS M d ison Wi c 1261-1268 ltJll2b) olu te content and concentra tion-Measuremen t of solute conshy

~rltill n utiing soil wa ter e)(traction Porous m a trix sensors in MetJlOds ofsoil 1 [ll1rt 4 Physical methods J H Dane and G C Topp eds SSSA Book

I~ )n i SSSA Madison Wisc 1269-1273 I~OOj) Ceosp atial measurements of apparent soil electrical conductivity ii r cterizing spatial variability in Soil-water-solu te process cill7racterizlshylit integrated Ilpproach J Alvarez-Bened i and R Munoz-Carpena eds

( I r lioea Ra ton Fla 639--672 n LJ L emlllo M L K Vaughan P J Rhoad es J D and Cone D C

I Eva luation of GIS-linked model of salt loading to groundwater f IrQII QUill 28 47]-480

11 D L find Hendrickx J M H (2002) Solut con tent and concentrationshylin-Ll mtasu rement of solute concentration E lectrical resistivity-Wenner

I in Methods of soillll1alysis Part 4 Physical methods J H Dane and G C rpLis Agronomy Monograph No9 SSSA Madison Wisc 1282-1287

10 D t Kaffka S R Hopmans J W Mori Y Lesch S M and Oster J D (1) Assessment and field-scale mapping of soil quali ty properties of a

Iml-5od ic soil Geodemw 114 231-259 LJ L and Lesch S M (2003) Application of soil el ctrical conductivity

bull 11 bion agriculture Theory principles and guid lines Agron f 95 i71

- (2005a) Apparent soil electrical conductivity measurements in agricu lshyJr~ COll1p11 Electron Agric 4611-43

- (2005b) haracte rizing soil spatial variability with apparen t soil electri-Ironductivity 1 Survey p rotocols C07llPtit Electron Agric 46 103- 133

- (200Se) Character izing soil spatiaL va riability with appar ent so iL electrishyII clIlductivity I Case study COliput Electron Agric 46 135-152

n1Ul D L Lesch S M Os ter J D and Ka ffka S R (2006) Monitoring manshyl~ tent-induced sp abo-temporal chang in soil quality through soil sampling JinCted by apparent elec trical conductivi ty Geaderlllll 131 369-387

332 AGRICULTURAL SALINITY ASSESSMENT AND MAIJAGEMENT

Corwin D L Lesch S M ShoUSt~ P J Soppe R and Ayars J E (2003b)middot tifying soil proplrties that influence cotton yield using soi l sampling by apparent soil electrical conductivity Agron f 95352-364

Corwin D L and RlloadesJ D (1982) An improved te hniqu forrlptrmt

soil electrical conductivity-depth relations from above-ground measurements Soil Sci Soc Am J 46 517- 520

--- (1984) Measurement of inverted electrical conductivity pfl)fil~

electromagnetic induction Soil Sci Soc Am f 48 288-29l --- (1990) Establishing soil electrical conductivity Depth relation

electromagnetic induction measurements ComnlUn Soil Sci Plallt A1I1I121 12)861-90l

Csillag F Pasztor L and Biehl L L (1993) Spectral band selection fu rth aCkrization of salinity status of soils Remote Seils EiIViron 4 231-2-tl

Dalton F N (1992) Development of time domain rcflectom try for soil water content and bulk soil electrica l conductivity in Advances ill ment of soil physical properties Bringing theory into practice G C Topp 1

Reynolds and R E Gre n eds SSSA Splcia~ Publication 30 SSSA Wise 143-167

Dalton F N H erkelrath W N Rawlins D S and Rhoades J D (198-t) domain reflectometry Simultaneous measurement of soil water CLlnt r electrical conductivity with a single probe SCiCIIC( 224 989-990

Dane J H and Topp G C (eds) (2002) Methods of soil analysis Pari 4 methods SSSA Book Series 5 SSSA Madison Wise

Dehaan R L and Taylor G R (2002) Field-d rived p ctta of saliniZll1 and vegetation as indicators of irrigation-induced soil saliniza tiun R Sens Environ 80406-417

de Jong E Ballantyne A K Caneron D R and Read D W (1979) ment of apparent electrical conductivity of soils by an electromagnetic tion probe to aid salinity surveys Soil Sci Soc Am J 43 810-812

Diaz L and Herrero J (1992) Salinity est imates in lrrigated soils using magnetic induction Soil Sci 154 151-157

Dobrin M B (1960) [Iltmnlletion to geophysical prospecting McGraw-Hi lI York

Doolittle J A lndorante S L Potter D K Hefner S G and McCauley Ii (2002) Comparing three geophysical tools for locating sand blows in ltIII soils of southeast Missouri f Soil Water COl7serv 57(3)175-182

DooLittle J A Suddu th K A Kitchen N R and Indorante S J (19Y-t ) f mating depths to c1aypans us ing electromagnetic induction methods I Waler COllscrv 49(6) 572-575

Drommerhausen D L Radcliffe D E Brune D E and Gunter H D (I lectromagnetic conductiVity surveys of dairies for groundwater nitr~t

I7virol7 Qual 24 1083-1091 Dualem (2007) DUALEM-2 Dualem Ine Milton Ontario

wvvwdualemcomdocumentshtml acce sed June 2007 Eigenberg R A Doran J W Nienaber J A Ferguson R B and Wood~

B L (2002) Electrical conductivity monitoring of soil condi tion and 1 able N with animal manure and a cover crop Agric Ecosyst El1viroll 183-193

333 NACUvl1 r

ivity PI(il

ec tiol1 fllr th bull 43 211 -2 2 try for nWI ur iVI1 Irs IJ 1111

C Torr ~ I S SA r1ldl

D (1 ltJ8J J 11m ilt r con I nt I 190

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v-Hill ll

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LBORATORY AND FIELD MEASUREME NTS

Korthals R L and Neinaber J A (1998) Geophysical electroshyurc) method applied to agricultural waste sites J Environ Qual

~N

K and Nimaber J A (1998) Electromagnetic survey of cornfield bull Ittl manure applications J Environ Qual 27 1511-1515

I oil cclllrilictivity map differences for monitoring temporal changes in an t filM ASA Paper o 992176 ASAE St Joseph Mich 111 Id(lI lificatio1 of Il utrient distribution at abandoned livestock Inal111re

I lIillX r Ic lromagnetic inductioll ASAE Pap r N o 012193 ASAE Ilnit md tilll1al Meeting July 3D-August 1 2001 Sacramento California

I I~ph Mich I M Woodson W D Malo D D Clay D E arison C G and (llt)9 ) Spatial variability in corn rootworm d is tribution in relation

1111 tl riable soil factors and crop condition in Proc 4th Int COil Oil

~rjCIIl lll rc 51 Palll Mil111 lsota JlIly 19-22 1998 P C Rob rt R H nJ W E Larson eds ASA-CSSA- A Madison Wisc 523-533 l l (1974) OUlm nts on A technique using porous cups for water

ling til any d pth in the unsaturated zone by W W Wood Water illlt ]0 1049

II ) Buchleiter G W and Bro lahl M K (2005) Ch aracterization of tltltrkal conductivi ty variability in irrigated sandy and non-saline fields I~rndtl Tmlls ASAE 48(1) 155-168 T L dnd La uterbach M A (1999) Soil map unit composition and scale trpil1 rela ted t interpre tations for precision soil and crop management

J in Proc 41h In Con 011 Precision AgriClllture St Palll Minnesota july ~ rQ98 r c R bert R H Rust and W E Larson eds ASA-CSSA-SSSA

tlJMn Wise 239-251 In D V and Stewart M T (1986) Transient electromagnetic sounding

~lIlundwJter Geophysics 51 995-1005 l W Sudduth K A and Kitchen N R (2001) Delineation of site-speshy

lTIlOdgement zones by unsupervised classifica tion of topographic attribshy and soil ( (mcal conductivity Trans A5A 144 (1) 155-166 ni R S Branson J L Ammons J T and Leonarmiddotd L L (2001) Surveying h~l water on anthropogenic soils using non-intrusive imagery TrailS L J-I 195~ 1963

mJR S Yoder R E Ammons J T and Leonard L L (2002) Mobilizing If Cl ing of aUconductivity llsing electr magnetic induction Appl Elg

18(1) 121- 126 S L WalJac J F Caccetta p and Wheaton G A (1995) Detecting and mlllitoring salt-affected land CSIRO Mathemati al and Informa tion Sciences wcmiscsiroau rsm research salmapmon salmapmonhtml accessed lr~ 2007 and Tiemann R (1975) Determination of the complex permittivity

111m thin-sample time domain r flectometry Imp roved analysis of the step fmiddotp()n~e waveform Adv Mol I~elax Processes 7 45-59 lh 1I S Khali1ian A Han Y J Dodd R B Wolak F Land Keskin M ~X I1) Variable depth tillage based all geo-referellced soil cIl1llpaction data in coastal I~ill r~i(Jll of South Carolina ASAE Pap er No 011016 2001 ASAE Annual

334 AGRICULTURAL SALINITY ASSESSME NT AND MANAG EME T

International Meeting July 30-August 12001 Sacramento California A St Joseph Mich

reenhouse J P and Slaine D D (1983) The use of reconnaissance electron netic methods to map contaminant migration Ground Water Ma lit Rei 47- 59

- -- (1986) Geophysica l modelling and mapping of contamina ted grolllll

ter arou nd three waste disposal sites in southern Ontario all GeoecliI 372-384

Haines B L Waide J B and Todd R L (1982) Soil solution nutrient con trations sampled with tension and zero-tension Iysimeter Report of dix ancies Soil Sci Soc Am j 46 658-661

Halvorson A D and Rhoades J D (1976) Field mapping soil conductilit delineate dryland seeps with four- electrod e techniques Soil Sci 50( An 44571-575

Hanson B R nd Kai ta K (1997) Response of elec tromagnetic conduclil meter to oil salinity and oil-water content j lrrig Drahl Eng 123 141-1

Ha rned H S and Owen B B (1958) The physical chemistry of electrolyte olu Reinhold Publishing Corp N ew York

Hart G L and Lowery B (1997) Axial-radial influence of porous cup soil ~ tion sa mplers in a andy soi Soil Sci Soc Am J 61 1765-1773

Heimovaara T J Focke A G Bouten W and Verstraten J M (1995) As ing temporal va riations in soil water composition with time domain reflect etry Soil Sci Soc Am J 9689-698

Hendrickx J M H Bae rends B Raza Z 1 Sadig M and Chaudhry M (1992) Soil sal inity assessment by e lectromagnetic inductil n of irrigul land Soil Sci Soc Am J 56 1933-1941

Hendrickx J M H and Kachanoski R G (2002) Solute content and concentr tion Indirect measurement of solute concentration N oninrrusive elc( tram netic induction in Mtlhods of soil analysis Part 4 Physical methods J H D and G C Topp eds AgTOnomy MonogTaph No9 SSSA Mad ison Wi 1297-1306

Herrero J Ba A A and Arag ues R (2003) Soil salinity and its distribuh de termined by soil sampling and el ctromagn tic techniqUls Soil Usc AI~m 19(2)119-126

Indo-Dutch Ne twork Project (IDNP) (2002) Il1do-Dutch lIetwork project I I met ology for identification of waterlogging and soil salinity conditions using r 1I1ue

ing CCSRI KamaJ India and Alte rra -ILRl Wageningen The NetherlanQ~

Inman D J Freeland R 5 Yoder R E Ammons J T c nd Leonard L L (2eX) Evaluating CPR and EMI for morphological studies of loessial soils Soi ~

166(9)622-630 Jacobsen O H and Schjemning P (1993) A laboratory ca libra tion of It

domain reflectometry for soil water measurements lncI uding effects of bumiddot d ensity and texture j Hyd rol 151 147- 157

Jaynes D B (1996) Mapping the a real dis tribution of soil parameters with ( physica l techniques in Applications of GIS to the modeling of nOll-point source II lutmzts in the vadose zone SSA Specia l Publica tion No 48 D L Corwin and K Loague eds SSSA Madison Wis 205-216

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LABORATORY AND FIELD MEASUREM ENTS 3 5

D B Colvin T and Ambuel J (1993) Soil type and crop yield determinamiddot 1 rMllld conductivity surveys ASAE Paper N o 933552 1993 ASAE Winshy

I tin D cember 14-17 1993 Chicago ASAE St Josep h Mich fJ B ovak J M Moorman T B and Cambardella C A (1995) stishy herbicide partition coefficients from electromagnetic induction measshy

ntgt f Ell viron Qual 24 36-41 K Doran j W Duke H R Weinhold B L Eskridge K M and

lhll1 J F (2001) Field-scale e lectrical conductivity mapping fo r delinshy ltJil condition oil Sci Soc A lii J 65 1829-] 837

n 1 A Savage M J Moolman J H and du Pleiss H M (1997) EvalshyI Il f Cltllibration methods for interpreting soil salinity from elec tromagshy~ lIIauclion measuremen ts Soil Sci Soc Am f 61 1627-1633

ki R C de Jong E and Van-Wesenbeeck I J (1990) Field scale patshy-llr~oilllater t rage from non-contacting measurements of bulk ellctrical

(Idulhlmiddotity Call J Soil Sci 70 537-541 lIdj R G r go rich E G and Van-Wesenbeeck I J (1988) Estimating lIIJ riations of soil water content using noncontacting electromagnetic

udi methods Can J Soil Sci 68 715-722 ~ I L(sch S M Bali K M and Corwin D L (2005) Site-specific manshy

_men t in salt-affected sugar beet fields using electromagnetic inductive rJ](Ids COIIp llt Electron Agric 46 329-350 II rJennings Walker M and Layson H R (1987) Monitoring moisture

lr4tilln in the vadose zone with resis tivity Ground Water 25562-571 ufJI B R Robert P C and Hug ins D R (1998) Use of non-contacting

I trltlIlldgnrtic inductiv method for estimating soil moisture across a landshypl (IJlIIIZIIIl Soil Sci Plant Anal 29 2055-2065

n R Sudduth K A and Drummond S T (1996) ~lapping of silnd _poition from 1993 Midwest floods with electromagnetic induction measureshynt I Soil Water Conserv 51(4) 336-340

Ilncnko A Bollero G A Omonode R A and Bullock D G (2002) MlOti tative mapping of soil drainage classes using topographical da ta and

JJ dectrical conduc tivity Soil Sci Soc Am J 66 235-243 11 S M (2005) Sensor-direc ted response surface sampling designs for charshy~rizing spatial variation in soil properties Compllt Electron Agric 46 (1-3)

P -17lJ M Con-vin D L and Robinson D A (2005) Apparent soil electrical

nnductivity mapping as an agricultural management tool in arid zone s ils Imlll t Electroll Agric 46 (1-3)351-378

h S M H rrero J and Rhoades J D (1998) Monitoring for temporal 1mges in soil alini ty using electromagnetic induction techniques Soil Sci

AlII f 62 232-242 hS M Rhoades J D and COlVv in D L (2000) ESApmiddot95 version 2lOR User d Ill turinl guide Research Report 146 USDA-ARS Us Salinity Labora tory

Riveroide Calif h S 1 Rhoades J D Lund L J and Corwin D L (1992) Mapping soil

gtdl inity using calibrated electromagnetic measurements Soil Sci Soc Am J ib 40-548

I

1

~

336 AGRICULTURAL SALINITY ASSESSMENT AND MANAGEM ENT

Lesch S M Strauss D L and Rhoades J D (19951) Spatial prediction of salinity using electromagnetic induction techniques 1 Statis tical prcdil models A comparison of multiple linear regmssion and cokriging 1 RCSOllt Res 1 373-386

--- (1995b) Spatial prediction of soil salinity using electromagnetic ind tion techniques 2 An efficient spatial sampling algorithm suitable for mullip linear regression model identification and estimation Water Reso llmiddot Res I

3R7-398 Lobell D B Lesch S M Corwin D L Ulmer M G Anderson K A Pottl

L Doolittle ] A Matos M R and BaIt s M J (2010) Regional-scale a ment of soil salinity in the Red River Valley using multi-yea r ODlS EVI NDVI J El1v iron Qual 3935-41

Lobell D B Ortiz-Monasterio J 1 Gurrola F c and Valenz uela L (21Xr Identification of saline oils with multiyear remote sensin g of crop yi elds Soil Sci Soc Am J 71 777-783

Madrigal L P Wicgand C L Meraz J G Rubio B D R Estrada X c Ramirez O L (2003) Soil salinity and its effect on crop yield A study uU satellite imagery in three irr igation districts IngCllieria Hidralilica EI1 MCl 1883-97

Mallants DVanclooster M Toride N Vanderborght L van Genuchten 11 and Feyen J (1996) Comparison of three methods to calib ra te TORmiddot monitoring solute mov ment in undisturbed soil Soil Sci oc Am f

747-754 Man kin K R Ewing K L Schrock M D and Kluitenbelg J (1997) 11

lIleasurement and mapping ofsoil salinity ill salille s(eps ASAE Pap r No 9711 ~i

1997 SAE Winter Meetings December 1997 Chicago ASAE St j(UP Mich

Manki n K R and Karthikeyan R (2002) Fi ld assessment of saline seep rem diation using electromagnetic induction Trans ASAE 45(1) 99- 107

Maas E V 1986 Salt tolerance of plants Appl Agric Res 1 12-25 Marion G M and Babcock K L (1976) Predicting specific conductance ao

salt con entration of dilute aqueous solution Soil Sci 122 181-187 McBride R A Gordon A M and Shrive S C (1990) Estim ating forest

quality from terrain measurements of apparent electrical conductivitv Sci Soc Am J 54 290-293

McNeill J D (1980) Electromagnetic terrain conductiv ity measuremellt at low illdll tioll lluJIlbcrs Technical N ote TN-6 Geonics Ltd Mississauga Ontarll Canada

--- (1992) Rapid accurate mapping of soil sa linity by eectromagn~li

ground conductivity meters in Adval1ces in measuremel1 ts of soil physimlllrlt1 ties Bringing theory into practice SSSA Special Publication No 30 C Torr W D Reynolds and R E Green eds ASA-CSSA-SSSA Madison Wi 201-229

Metternicht G (2001) Assessing temporal and spatial chang of alinity ugtin fuzzy logic remote sensing and GlS Founda tions of an expert system h Model 144 163- 179

Metternicht G and Zinck J A (1997) Spatial discrimination of alt- un sodium-affected soil surfaces Int J Rcmote Seils 18 2571- 2586

LABORATORY AND FIELD MEA URE

_ _ (2003) Remote sens ing of soil salinity Pot ifllor SCIIS Ellvimn 85 1- 20

11u~enot 5 Pouget M and Epema G F (1993) Rerr lIis Relllote Seils Rev 7 241-259

Illr~ltm C L s Norman J M Wolkowski R P L md Schuler R (2000) Two approaches to mapp EM-38 measurements and inverse yield modeling PI ci -ioll Agrhlltu re Minneapolis Minnesota lilly 1

H Hust and W E Larson eds ASA-CSSA- CD-ROM]

lll lll W G (2001) Collectillg spatial data Optimlllll d tOIll fields 2nd ed Physica-Verlag Heidelberg

lfitler W G and Zimmerman D L (1999) Optimal mltion Ellvironmetrics 1023-17

lUl gtton W D Bushue L Doolittle J A Wndres 11lt)4) odium affected soil identification in soutlshymilgn tic induction Soil Sci Soc Am J 58 1190- 1

(lbes D c Armstrong M L and Close M E (2000 leachate plume and flow channels in coastal sand unland usin g a shallow electromagnetic survey r 12amp-336

iJuist J E and Blair M S (1991) Geophysical trlI m scription and case history Geophysics 56(7

rlln J G (2003) Determining salinization extent i ll1d estimating chloride mass using surface bor magnetic induction methods Water Re Ollr Res

Ranjan R S Karthigesu T and Bulley N R (1995) IIdie method for detecting lateral seepage arolllld lila 1lper No 952440 ASAE St Joseph Mich

llulu n -Rasmussen K (1989) Aluminum contamir d( id soil solution isolated by means of porcelain S

Q5-102 1llCC C F (1998) Simple method for determinin

lime domain re flectornetry systems Soil Sci Soc

Rllllmeier R P and Wilcox L V (1946) A critiqlli CI nl ntrations from the electrical conductivity of 281 -293

Ihu des J D (1992) Ins trumental field method middot( flllllces in measurement of soil physical pTOperties SA Special Publication No 30 G C Topp W D tds SSSA Madison Wisc 231- 248

__ (1 993) EIectIical conductivity methods for n ~linity in Advances in agronomy D L Spar~ EI

_an Diego Calif 201- 251 Rh ltIdes] D Chanduvi F and Lesch S (1999b) SOi

wei interpretation of electrical condllctivity meaSl( Drlinage Paper N o 57 Food and Agriculture (

al ions l~Qme

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~line eep r mlshy9- 107 -25

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RlnlOte sen ing of soil salinity Potentials and constraints lmirt l 85 1-20

f Iuget 1vl and perna G F (1993) Remote sensing of salt affected I -lIlS Rev 7 241- 259

I -Jorman J M Wolkowski R p Lowery B Morgan G D ultf It (2000) Two approaches to mapping plant available water

n middotIllrtlmcnts and inverse yield modeling in Proc 5th Int Conf on hntrtillirc Milll1eapolis Minnesota July 16-19 2000 p C Roberts

Ru t md W E Larson eds ASA-CSSA-SSSA Madison Wise 14

R 1 POOl) Collecting spatial data Optimum design of experiments for ranshyIf 2nJ Id Physica-Verlag Heidelberg

t md Zimmerman D L (1999) Optimal designs for variogram estishyn flliiro llmltric 1023-37

D Bushue L Doolittle J A Wndres T J and lndorante S J ~(ldi um Jffect d oil identification in south-central Illinois by electroshy

mtl induction Soil Sci Soc Am] 58 1190-1193 gt ( rrnstrollg M L and Close M E (2000) Delineation of a landfill

i die plume and flow channels in coastal sands near Christchurch New middotd using il shallow electromagnetic survey method Hydrogeol J 8(3)

)I 1l6 ~lll t J E and Blair M S (1991) Geophysical tracking and data logging sysshy m Dtmiddot cription ilnd case history Ceophysics 56(7)1114-1121 t j G (2003) Determining salinitation extent identifying salinity sources e~t imating chloride mass using surface borehole and airborne electroshy

mlif1~ t ic induction methods Water Reso llr Res 39(3) 1059 101 R 5 KarUligesLl T and Bulley N R (1995) Evaluation of an eleetromagshyt TlH t(Jd for detectillg lateral seepage around lIlanure storage lagoons ASAE

Iaper No 952440 ASAE St Joseph Mich ~Jund-Ramussen K (1989) Aluminum contamination and other changes of tit oil solution isolated by means of porcelain suction cups J Soil Sci 40 1~102

C F (1998) Simp le method for determining cable length resistance in me domaLn retlectometry syst m s Soil Sci Soc Am ] 62 314-317

Ihm ier R F and Wilcox L V (1946) A critique of estimating soil solution mccnlrations from the electrical conductivity of saturated soils Soil Sci 61

]1-293 ~huldes J D (1992) Instrumental field methods of salinity appraisai in

idll1l1ces ill mea lIrClIlcnt of soil physical properties Bringing theory into practice S Special Publication No 30 G C Topp W D Reynolds and R E Green

cl~ SS Madison Wise 231-248 - - (1993) Electrical conductivity methods for measuring and mapping soil

alinity in Advances ill agrollOnty D L Sparks ed Vol 49 Academic Press ~l n Diego Calif 201-251

RhOadesJ D Chanduvi F and Lesch S (1999b) Soil salinity assessllent Methods IIIld il1 terpretation of electrical COlldliCtivity measuremcllts FAO Irrigation and Drainage Paper N o 57 Food and Agriculture Organisation of the United I ntions Rome

338 AGRICULTURAL SALI NITY ASSESSM T AND MANAGEM T

Rhoades J D and Corwin D L (1981) Determining soil electrical conductil it depth relations using an inductive electromagnetic soil conductivity mlltr Soil Sci Soc AII1 [ 45 255-260

~-~ (1990) Soil electrical conductivity Effects of soil properties and april tOn to sOLI saitmty appraisa l COIllIl1Un Soil Sci Plant Ana 21 37-860

Rhoades J D Corwn D L and L 5ch S M (1999a) Geospa tial me u ments of sod electncal conductivity to assess soil salinity and diffuse sa lt hl II1g from irrigation in Assessmellt of nOll-point source pollitior ill the liJJ zonc D L Corw~n K Loague and T R Ellsworth eds G opb Isical Mll1~

graph 108 Amencan Geophysical nion Washington DC 197-215 Rhoades J D and H alvorson A D (1977) Electrical condllctivil1lllctim middot

detccwg and delineating saline seeps and measuring salinity inllortlzert Crent lJ1J sOtls ARS W-42 U D -ARS Western Region Berkeley Calif 1--45

Rhoades J D and Loveday J (1990) Salinity in irrigated agricultur in Irri~

tlOn of allculturai crops Agronomy Monograph No 30 B Stewart and U R elsen cds SSSA Madison Wisc 1089- 1142

Rhoa~es J D Manteghi N A Shouse P L and Alves W J (1989a) Es timolttr sod saLInIty from saturated soil-paste electrical conductivity Soil Sci 50 tit [53428-433

~~- (1989b) Soileleclrical conductivity and soil salinity New formulati(lJ middot and cJlibration Soil Sci Soc Am f 53 433-439

Rhoades J D Raats P A c and Prather R J (1976) Effects of liquid-plu electn al cond uctiVity water content and surface conductivi tv on bulk ol electrical conductivity Soil Sci Soc Am f 40 651-655 I

Rh~ades J DShouse P J Alves W J Manteghi N M and Lech S M (9YUI Det rmmIng soil salImty from soil electrical conductivity using diffcr~n

m odels and estimates Soil Sci Soc Am J 54 46-54 Russo D (1984) Design of an optimal sampling ne twork for es timating the l1ri

ogram Soil Sci Soc AnI T 48 708-716 Salam~ R B Bartle G Farrington P and Wit on V (1994) Basin ge morphomiddot

logICal controls on the mechanism of recharge and disch rge and its effect on sal t storag nd mobllizatlOn Comparative study using geophysical surw J Hydrol 155(12) 1-26

ScanlonB R Paine J and Goldsmith R S (1999) v luation of electromaj netic mduchon as a reconnaissance technique to characterize unsaturated nUl

In an a rid setting Ground Water 37(2) 296-304 Sharma R Saxena R K and Verma K S (2000) Reconnaissa nce mappin)

and management of salt-affect middotd soils using sate liitl images lilt J Rcfllol SellS 21 3209-3218

Sheets K R and Hendrickx J M I-L (1995) on-invasive so il water conten t measur m ent using electromagnetic induction Water Reottr Res ~l 2401-2409

Slavich p G and Pett rson G H (1990) Estimating average rootzone salin itl from electromagnetic induction (EM-38) measurements Aust J Soil T~c 28 453-463

Smith C N Parrish R S and Brown D S (1990) Conducting field studies for testmg pesh deleaching models Int f EIlViroll Anal Clzem 39 3- 21

Spaans E J A and Baker J M (1993) Simple baluns in paraUel probes for tinl domam reflectometry Soil Sci Soc Am J 57 668-673

LABORATORY AND FIELD M ~

I D L ed (1996) Methods of soil analysiS f ~M~

Book Series 5 SSSA Madison WISe troh ] C Archer S R Doolittle J A and WI

daphic discontinuities with gTound-penetratl induction Landscapc Ecol 16(5)377-390

troh] c Archer S R Wilding L and Dooh influence of subsoil heterogeneIty on vegetll tl

l tl1 Texas using electromagnetiC inductIOn ~ I M vst 111 Call middotge Station Texas The statlOll 0

L bull D L ~ nd Taber P (2007) ExtractCJtem so)-UdreL Cl I

tv Lilboratory Riverside Calif tl K A and Ki tchen N R (1993) Electro n

Ulll U 1

pI it depth ASAE Paper N o 91531 1993 ASp 12-171993 Chicago ASAE 5t Joseph Mich

tudduth K A Kitchen N R Wiebold v J E Bullock D G Clay D E Palm H L Pierce K D (2005) Relating apparent electrical con the north-central USA Compul Electroll Agn

1 d iurd W M Gledart L P and Sheriff R E (1 Cambridge U niversity Press Cambridge K

rtw mpson S K (1992) sampliilg John W~ley an J L 1981 Detectmg mtl

r~pp C and 0 aVIS J cracks by time-domain refiectom try Ceoder

C C Davls J L and Annan A P (1980)IOPPI 1 f C I

of soil water content Measurement U1 COd

[icOllr Res 16 571-582 _ (1982) Electromagnetic determination a

Applications to wetting fronts and steep gn

b72-678 middot t t ls J Ahmed M F and Odeh 1 O A

l nan all If

ElectromagnetiC Sensing System (MESS) to soil salinization in an irrigated cotton-grow

330-339 riantafilis J Huckel A 1 and Odeh 1 O A

prediction methods for e~timati~g field~scal E binations of ancillary vanables Sod Sel 16(

Trial1iltafilis J and Lesch S M (2005) Map ele tr m agnetiC induction techniques CO1l

Tweed S 0 Leblanc M Webb J A and L dwa~

sensing and GIS for mappIng groun salinity-prone catchments southeastern Au

U Salinity Laboratory (1 54) DwgnOS1S al1d US Dep artment of Agriculture Handbook

Hi e Washington DC alliaDt R Dorfman A R and Royall R ~

11l1 a irtferetlce A prediction approach John Wl ll c van d(r Lelij A (1983) Use of an electromag

for mapping of soil salil1ity Intexnal Report Commission NSW Australia

middotAIJD MA NA GEMENT

lin s il el trmiddot jb ec lca conducti iI

netIc sad conductio tV1 y In lt(f

at soil p roperties and apr l dshy

middot llnllt AIaI 2] 8 7---86(J lY99a) bull

u

eo p o bal mca~url I salmlty and di ffu st sa [ IOlUshyr sou rce POllitio N ill tlr 1(11 th II Ir ed Geoph sical Mon)shyngton DC 197- 21 ) - ~1Ci71 condllctivity Ilcthl1d II allillty lIZ nortZern Crll7t 1111_ middotkel y aLif ] -45 igated aOTicul tufe I omiddot In 1111(11 0 30 B A St w a rt and 0 R

es W f (1989a) Est (mallng lductivity Soil Ct C I

JOe III

I aLini tv e f J W ormula tiol1

76) Effects of liq uid-p ha I conductivity on bulk - 1

-~ ~U I-6Xl

M an d Lesch S_M (1990) nductl vltv uSing d t-f4 J ( nml

ork fo r timahn g th( v ri shy

(1994) 8 middot a m geomorpho_ dIscharge and its eHct un slllg geophysica l Surveys

valuation o f lectromag_ racterize unsatura ted flo

Reconnaissance m apping te Images fnt_j RCIIote

iasive soil wa ter con ten t Water Resoll r Res 31

verage rootzone salinity ts A J middot list j lot Res 28

ducting field studies for Chem 39 3-2l

parallel probes for time


rk D L ed (1996) Methods of soil analysis Part 3-Chelllicai lIIetliods SSSA ~lk Scries 5 S SA Madison Wisc -It J c Archer S R Doolittle J A and Wilding L P (2001) Detection of od phic discontinuities with ground-penetrating radar and electromagnetic

in ti (dion LalldsCi7pe Ecol 16(5) 377-390 h Jc Archer S R Wilding L P and Doolittle J A (1993) Assessing the intl uence of subsoil heterogeneity on vegetation in the Rio rande Plains of (Illth Texas using electromagnetic induction and geographical information -tl1m College Station Texas The Station March 1993 39-42

~l D L and Taber P (2007) ExtractCzelll software Version 1018 Us Salinshy1 Ldboratory Riverside Calif Juth K A and Ki tchen N R (1993) Electrolllagnetic induction sensil1g of clayshy

bull It depth AS E Paper No 931531 1993 ASAE Winter Meetings December 12- i7 1993 Chicago ASAE St Joseph Mich

Jriuth K A Kitchen N R Wiebold W_ L Batchelor W D Bol1ero G A Hullock D G Clay D E Palm H L Pierce F L Schuler R T and Thelen 1gt D (2005) Relating apparent electrical conductivity to soil properties across the north-central USA Comput Electron Agric 46 (1-3) 263--283

dtord W M Gledart L P and Sheriff R E (1990) Applied geophysics 2nd cd Cambridge University Press Cambridge UK (lm[son S K (1992) Saltpiing John Wiley and Sons Inc New York

tlPPC cand Davis J L 1981 Detecting infiltration of water through the soil racks by time-domain reflectometry Geoderma 2613--23

((PPG cDavis J L and Arman A P (1980) Electromagnetic determination (I f soil water content Measurement in coaxial transmission lines Water Rcsollr Res 16 574--582

- - (1982) Electromagnetic determination of soil water content using TDR l Applications to wetting fronts and steep gradients Soil Sci Soc Am f 46 672-678

ri(Otaiilis J Ahmed M F and Odeh L O A (2002) Applica tion of a Mobile rtcctromagnctic Sensing System (MESS) to assess cause and managemen t of ~o il salinization in an irrigated cotton-growing field Soil USC Mgmt 18(4) 330- 339

Iriantafilis j Huckel A I and Odeh 1 O A (2001) Comparison of statistical prediction methods for estimating field-scale clay content using different comshybinations of ancillary variables Soil Sci 166(6)415-427

friHldtafilis J Jnd Lesch S M (2005) Mapping clay content variation lIsing electromagnetic induction techniques Comput Electron Agric 46 203--237

fw(cd S 0 Leblanc M Webb J A and Lubczynski M W (2007) Remote sensing and GlS for mapping groundwater recharge and discharge areas in salinity-prone catclunents southeastern Australia Hydrogeol J 1575-96

Us Salinity Laboratory (1954) Diagnosis and improvement of saline and alkali soils Us Department of Agriculture Handbook No 60 Us Government Printing Office Washington DC

Valliant R Dorfman A H and Royall R M (2000) Finite populntioll sampling and inferellce A prediction appruaclz John Wiley and Sons inc New York

Ian def l elij A (1983) Use of an ciectromagnetic induction instrument (type EM38) for mapping of soil salillity Internal Report Research Branch Water Resources Commission NSW Australia

340 AGRICULTURAL SALI NITY ASSESSMENT AND MANAGEMENT

Vaughan P J Lesch S M Corwin D L and Cone D G (1995) Water conte on soil salinity prediction A geostatistical study using cokriging Soil Sci x Am J 59 1146--1156

Veris Technologies (2011) Products Veris Technologies Salina Ka a wwwveristccncom accessed January 21 2011

Verma K S Saxena R K BarthwaI A K and Deshmukh S N (19 ~

Remote-sensing technique for mapping salt-affected soils Int J Remote 5 15 ]901-1914

Warrick A W and Myers D E (1987) Optimization of sampling locations iur variogram calculations Water Resour Res 23 496-500

Wesseling J and Oster J D (1973) Response of salinity sensors to rapidh changing salinity Soil Sci Soc Am Proc 37 553-557

Wiegand C L Anderson G Lingle S and Escobar D (1996) Soil salinin eff ts on crop growth and yield lllustration of an analysis and mappin methodology for sugarcane J Plant Physiol 148418-424

Wiega nd C L Rhoades J D Escobar D E and Everitt J H (1994) Phott graphic and vid ographic observations for determining and mapping tht response of cotton to sOil-salinity Remote Sens Environ 49 212-223

Williams B G and Baker G C (1982) An electromagnetic ind L1ction techniqutmiddot for reconnaissance surveys of soil salinity hazards Aust J Soil Res 2n 107-118

Williams B G and Hoey D (1987) The use of electromagnetic induction h de tect the spatial variability of the salt and clay contents of soils Allst f 51 Res 25 21-27

Wilson R c Freeland R S Wilkerson J B and Yoder R E (2002) Imagillg fir lateral migration of subsurface moisture using electromagnetic indllctioll ASAE Paper No 0230702002 ASAE Annual International Meeting July 28-31 2002 Chicago ASAE St Joseph Mich

Wollenhaupt N c Richardson J L Foss J E and Doli E C (1986) A rapid method for estimating weighted soil salinity from apparent soil electrical conmiddot ductivity measured with an aboveground electromagnetic induction meter Call j Soil Sci 66 315-321

Wraith J M (2002) Solute content and concentration Indirect measurement of solute concentration Time domain reflectometry in Methods of soil alloiysi- Part 4 Physical metilods J H Dane and G C Topp eds Agronomy Monograph No9 SSSA Madison Wise 1289-1297

Zhu Z and Stein M L (2006) Spatial sampling design for prediction with estishymated parameters j Agric Bio Environ Statistics 1124-44

NOTATION

CEC = cation exchi 1ge capacity EC = el ctrical conductivity ECa = electrical conductivity of the bulk soil referred to as apparent

soil electrical conductivity EC = electrical conductivity of an extract of a saturated soil paste

LABORATORY AND FIELD MEASURH

~C I ~ electrical conductivity of satuated sil p Ee = electrical conductivity of a sOli solutIOn EM = electromagnetic induction when the mstn

to the soil surface EM = electromagnetic induction when the inS

pendicular to the soil surface EMI = electromagnetic inductIOn

ER = electrical resistivity IT = evapotranspiration

DVI = normalized difference vegetation mdex SP = saturation percentage

TOR = time domain reflectometry

341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te


- electrical conductivity of saturated soil paste - ~lectrical conductivity of a soil solution dtctromagnetic induction when the instrument coils are parallel

to the soil surface electromagnetic induction when the instrument coils are pershy

pendicular to the soil surface U - electromagnetic induction

~ electrical resistivity - evapotranspiration

1- normalized difference vegetation index - ~aturation percentage time domltlin reflectometry

296 AGRICULTURAL SALI NITY ASSESSM ENT AND MANAGEM ENT

and monitored This chap ter describes common field and laboratory t niques for measuring salinity in the soil and water w ith di u sian their practicability and reliability

FACTORS AFFECTING SOIL SALINITY

The accumula tion of soil salinity is a consequence f a variet pro esses some of which are illu trated in Fig 10-1 In arid and semian

fl areas for example where pre ipitation is less than evaporation salts lJ accumulate at the soil surface when the depth to the water table is I t r

than 1 to 15 m depend ing on the soil texture The accumulation of salts 11 r

the soil surface is the consequence of the upward flow of water and ur sequent transport of salts due to capillary rise driv n by the evaporatill p rocess However the most common ca use for the accumulation of ai DIRE is ET by plants w hich results in an increase in salt concentra tion IIi depth through the roo tzone (see graph in Fig 10-1) and th accumulatil Till

of salts below the rootzone The lev I of salt accumulation within an (lrator

below th r otzone due to ET depends on the fraction of irrigation or prl Ii I ir flwnt (

What Causes Salt Accumulation ftP~

FIGUR E 10-1 Variou s examples of how salts accumulate in soil

rm be ClIJ1gttil m ntl IIll r

1 ) l

lion e llt~ I

prop I

Ilw 1 lldiu [ II Ilf 1tIi

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~





(UI-




log TSS = 0990 + 1055 log EC (r2 = 0993)




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METH SOIL

1111lt11

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h -II


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he

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40 60

80 - 8 100 I

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can




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ctors

pin

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)













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t








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b

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bull bull










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[mS m )

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1220- 290

1290- 410




































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the inst prop 11

bull I eIDOt

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RpoundFERENC


329


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I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

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sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































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ivity PI(il




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-Ichen depos mtnls

krd ch [ U Ultl n

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acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

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c95) A~shy

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NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







lt NA E ENl




~tion























~





(UI-




log TSS = 0990 + 1055 log EC (r2 = 0993)




ECs C = It EC (1(l

I here 114t)=1 I

METH SOIL

1111lt11

Elect

h -II


Ie Ii 111

he

In 0

rntl

Ii lIt I

11

middotNA EM[NT


IO-t

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(10 2










( II



(10

(10-5)





bull












n one xtrl t














SP=20 10

40 60

80 - 8 100 I

E 6(J tJ- 4

tI

0 W 2

1 2 3 4 5 ECp(dS mshy1)



Platinum electrodes

can




Manifold

Vacuum

Solution



Spring

Housing



303 -JAGEME T


ctors

pin

Spring
















)













lldl

FGLI 11111--1

(2(JU2 i

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ilgts~ Ih n




In 11

k

J

rt

ldl












Current

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t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

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0 GI 15 W 10

5

~---------7--~------

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o 1 2 3 4 5 6 7 8 910 1112

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313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




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~~111 ) a n ~

(L lYin

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( - nlllln (



ry MEASUREM ENT








bull f Imiddot








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(al


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ui l ample





e






















ECa Survey

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Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

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](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


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urcm Jllhn n

han Lmiddotltinl

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tlnl~

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-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


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r i i on Wi~~



























I

1

~









































al ions l~Qme

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ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



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-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te











~





(UI-




log TSS = 0990 + 1055 log EC (r2 = 0993)




ECs C = It EC (1(l

I here 114t)=1 I

METH SOIL

1111lt11

Elect

h -II


Ie Ii 111

he

In 0

rntl

Ii lIt I

11

middotNA EM[NT


IO-t

soil sol uti )


(10 2










( II



(10

(10-5)





bull












n one xtrl t














SP=20 10

40 60

80 - 8 100 I

E 6(J tJ- 4

tI

0 W 2

1 2 3 4 5 ECp(dS mshy1)



Platinum electrodes

can




Manifold

Vacuum

Solution



Spring

Housing



303 -JAGEME T


ctors

pin

Spring
















)













lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

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penh I ri I JI(1r





(l~



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EMI at EC In

(I









cs for the mlcl 1I





(10- l



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ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


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I

1

~









































al ions l~Qme

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coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







middotNA EM[NT


IO-t

soil sol uti )


(10 2










( II



(10

(10-5)





bull












n one xtrl t














SP=20 10

40 60

80 - 8 100 I

E 6(J tJ- 4

tI

0 W 2

1 2 3 4 5 ECp(dS mshy1)



Platinum electrodes

can




Manifold

Vacuum

Solution



Spring

Housing



303 -JAGEME T


ctors

pin

Spring
















)













lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te













n one xtrl t














SP=20 10

40 60

80 - 8 100 I

E 6(J tJ- 4

tI

0 W 2

1 2 3 4 5 ECp(dS mshy1)



Platinum electrodes

can




Manifold

Vacuum

Solution



Spring

Housing



303 -JAGEME T


ctors

pin

Spring
















)













lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te








Platinum electrodes

can




Manifold

Vacuum

Solution



Spring

Housing



303 -JAGEME T


ctors

pin

Spring
















)













lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







303 -JAGEME T


ctors

pin

Spring
















)













lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te


















lldl

FGLI 11111--1

(2(JU2 i

NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







NAGEMlN I


ilgts~ Ih n




In 11

k

J

rt

ldl












Current

+-- r1 --1middot~Imiddot---------------- ~ --------------------~~1





EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te










EC lt0 _= ( 1000 ) (1~ G 21TR 1

t








307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







307


~AG[Mr1 I

mer arT] J a





Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te









Jnd El








45

40

- 35 ltT

E 30 25 U)

E 20

0 GI 15 W 10

5

~---------7--~------

0 ~~~~~~~~L-~~

o 1 2 3 4 5 6 7 8 910 1112

EC (dS m-1)a






12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







12



















(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te











(Ju

TimeDom




l3y mI rhe t is ~

here l

pa~ C it pro nd i

b Wl bull

bVLO

Bv r 11n bl

~middothL rmiddot

penh I ri I JI(1r





(l~



IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







IANAG uv1[N



EMI at EC In

(I









cs for the mlcl 1I





(10- l



er ther is nIl

ct 2 ( l )2 (10-9)E = = lvp (2J




(10-10)




(10-11)
















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te



















313

CTNG THE




Ee mea U rlml~111




References








(contillued)




















In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te


























In e t -1 (1 (2()05

phal p lei pa th iI

bull

II ng til bull I I


nlv th 011




- 111 I

Solid Liquid Air


11 11(

Ilfp~

I1C~ E at th

lire

mity








p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







p

















ospat

HIcl l1


nn ln l




l orwin I

~~111 ) a n ~

(L lYin

dir Id rl (lr pn



( - nlllln (



ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te








ry MEASUREM ENT








bull f Imiddot








Il in thi area












(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







(al


hll h w~rra

ui l ample





e






















ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te




























ECa Survey

Sample design



Map of Salinity




b

b 11
















321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te














321










































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te


































bull bull










EC







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







I

325 l-IANA [MEN T




e spatial EC I







IL SALINITY AT



[mS m )

20middot 105

105 middot160

1160 - 220

1220- 290

1290- 410




































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te





































Element Comment








-


bull I hI use 0

If d ive i

tnltiur n rninimil





or ab EI

the inst prop 11

bull I eIDOt

ping Sl

bltter Clll1d i l


RpoundFERENC


329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







329


I


f ftdd conditions

Ilnll~d()main r

I m ~ erature


gdr-Filrd A U




















obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







obit

ld-scalqt

s Bonrd H

























_ (2005

lUI LllIIl)





Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te








Seh pp E r (J

petronduc 1llIlil

](4) 372- 1lJO




sodic soif pring


1 Soil C~ i 110




ICC Pr nU t HII











































333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te





























333 NACUvl1 r

ivity PI(il




Part -I Phil I


179) MILl lJ


v-Hill ll

aule_ - I

iVS in dlUI ij

h 994) I II ods r 011



~N




































O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te



























O1d til

urcm Jllhn n

han Lmiddotltinl

IIlhngttor U1UO

II tit a h 11

tlnl~

u lI1d L



kcm W mij1ra


-Ichen depos mtnls

krd ch [ U Ultl n

llil ec Llsch S

acteriz 53-17

l~sch S I

llll1dLH COllprr

kch change Soc 1


Riversi Il eh S ~

lt linity i6540shy

I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







I M ENT

S CLIp soil I

c95) A~shy

ain r~flldom


~n COIlCllltr


r i i on Wi~~



























I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







I

1

~









































al ions l~Qme

NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







NAGEMr r


coJ riginf bull


Par MODIC I I



ifm 1fica EI AI





lting for st SII

d ucti vi ty ~(lJ

lit at low i lltilh

lga O nt rtio

~ctromagne ti


a lini ty L i 111

ystcm Eeo

of sat- and




















































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te





































Ulll U 1











l nan all If
















u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te












u



JOe III



-~ ~U I-6Xl










































NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te






















NOTATION










341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







341

~

emcnt 01 IlIlII1I

) ngrlt1ph

ith Ii

~te







CHAPTER 10 - USDA ARS

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Transcript of CHAPTER 10 - USDA ARS